- dovecot - dovecot.org

Blocking with RBLs
by Lefteris Tsintjelis 10 Jan '26

10 Jan '26

Hi, Is there a way to block with RBLs? I already have a really good and very trustworthy and accurate internal one that works extremely well and fast with my SMTP servers for years now. Is there a way to apply the same RBL to dovecot? Logs are really going crazy as they stopped with SMTP and started with IMAP for a while now since dovecot is wide open to these attacks. Anvil does not seem to do much here. I am looking for solutions other than fail2ban or anything similar to this. Lefteris

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Created DokuWiki entries for the migration from Dovecot 2.3 to 2.4.
by Klaus Tachtler 10 Jan '26

10 Jan '26

Hello everyone, Over the past few weeks, I have migrated from Dovecot 2.3 to 2.4 and documented this in my DokuWiki. I do not claim that this is complete, nor is it an all-encompassing description. It includes a configuration for Dovecot 2.3 and the respective migration to Dovecot 2.4. I implemented the following configurations: Dovecot ArchLinux Dovecot ArchLinux - SSL/TLS Dovecot ArchLinux - SASL Dovecot ArchLinux - Quotas Dovecot ArchLinux - Mail-Log-Schreibung Dovecot ArchLinux - Zlib-Komprimierung Dovecot ArchLinux - SQL Dovecot ArchLinux - SQL - Quota: SQL Dovecot ArchLinux - Sieve (Pigeonhole) Dovecot ArchLinux - Shares Dovecot ArchLinux - Master-User The DokuWiki entries are in German, but I think the code examples speak for themselves, and if necessary, a translation program can also be used. The Dokuwiki and my implementations can be accessed at the following link: https://dokuwiki.tachtler.net/doku.php?id=index#imap-server_dovecot_imap-se… The documentation was created using the Archlinux operating system, but can certainly be ported to other Linux distributions. I hope someone else might find my notes useful too? Best regards, Klaus Tachtler. -- --------------------------------------- e-Mail : klaus(a)tachtler.net Homepage: https://www.tachtler.net DokuWiki: https://dokuwiki.tachtler.net ---------------------------------------

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Re: Panic: file imap-sieve-storage.c: line 216 (imap_sieve_add_mailbox_event): assertion failed: (ismt->src_box == NULL || ismt->src_box == src_box)
by Stephen Callaghan 09 Jan '26

09 Jan '26

Having a similar issue: 2.4.2 (0962ed2104) via docker. Causing constant core dumping and my client keeps retrying blocking everything up. Any suggestions on how to identify the cause of the problem? S. Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Panic: file imap-sieve-storage.c: line 216 (imap_sieve_add_mailbox_event): assertion failed: (ismt->src_box == NULL || ismt->src_box == src_box) Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Error: Raw backtrace: #1 [unw_get_proc_name() failed: -10] -> #2 [unw_get_proc_name() failed: -10] -> #3 [unw_get_proc_name() failed: -10] -> #4 i_panic[0x7f13c0e8b7dd] -> #5 [unw_get_proc_name() failed: -10] -> #6 [unw_get_proc_name() failed: -10] -> #7 [unw_get_proc_name() failed: -10] -> #8 mailbox_save_alloc[0x7f13c11baf52] -> #9 [unw_get_proc_name() failed: -10] -> #10 [unw_get_proc_name() failed: -10] -> #11 cmd_move[0x5572105ab0ca] -> #12 command_exec[0x5572105c33f4] -> #13 [unw_get_proc_name() failed: -10] -> #14 [unw_get_proc_name() failed: -10] -> #15 [unw_get_proc_name() failed: -10] -> #16 [unw_get_proc_name() failed: -10] -> #17 client_handle_input[0x5572105c060c] -> #18 client_input[0x5572105c0847] -> #19 io_loop_call_io[0x7f13c0eb9798] -> #20 io_loop_handler_run_internal[0x7f13c0ebd48a] -> #21 io_loop_handler_run[0x7f13c0eb9aea] -> #22 io_loop_run[0x7f13c0eb9963] -> #23 master_service_run[0x7f13c0d7264b] -> #24 main[0x5572105db2a4] -> #25 [unw_get_proc_name() failed: -10] -> #26 __libc_start_main[0x7f13c0ae4ce0] -> #27 _start[0x5572105a62f0] Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Fatal: master: service(imap): child 555 killed with signal 6 (core dumped) Having a similar issue: 2.4.2 (0962ed2104) via docker. Causing constant core dumping and my client keeps retrying blocking everything up. Any suggestions on how to identify the cause of the problem? S. Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Panic: file imap-sieve-storage.c: line 216 (imap_sieve_add_mailbox_event): assertion failed: (ismt->src_box == NULL || ismt->src_box == src_box) Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Error: Raw backtrace: #1 [unw_get_proc_name() failed: -10] -> #2 [unw_get_proc_name() failed: -10] -> #3 [unw_get_proc_name() failed: -10] -> #4 i_panic[0x7f13c0e8b7dd] -> #5 [unw_get_proc_name() failed: -10] -> #6 [unw_get_proc_name() failed: -10] -> #7 [unw_get_proc_name() failed: -10] -> #8 mailbox_save_alloc[0x7f13c11baf52] -> #9 [unw_get_proc_name() failed: -10] -> #10 [unw_get_proc_name() failed: -10] -> #11 cmd_move[0x5572105ab0ca] -> #12 command_exec[0x5572105c33f4] -> #13 [unw_get_proc_name() failed: -10] -> #14 [unw_get_proc_name() failed: -10] -> #15 [unw_get_proc_name() failed: -10] -> #16 [unw_get_proc_name() failed: -10] -> #17 client_handle_input[0x5572105c060c] -> #18 client_input[0x5572105c0847] -> #19 io_loop_call_io[0x7f13c0eb9798] -> #20 io_loop_handler_run_internal[0x7f13c0ebd48a] -> #21 io_loop_handler_run[0x7f13c0eb9aea] -> #22 io_loop_run[0x7f13c0eb9963] -> #23 master_service_run[0x7f13c0d7264b] -> #24 main[0x5572105db2a4] -> #25 [unw_get_proc_name() failed: -10] -> #26 __libc_start_main[0x7f13c0ae4ce0] -> #27 _start[0x5572105a62f0] Jan 09 19:22:13 imap(SNIP)<555><rn1EcflH+ILwCwUB>: Fatal: master: service(imap): child 555 killed with signal 6 (core dumped)

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Problems building from source under Trixie
by William Silverstein 09 Jan '26

09 Jan '26

I am running Debian Trixie. I try building the, but the configuration fails: I tried building with: ./configure \ --prefix=/usr/local/dovecot \ --with-sql \ --with-mysql \ --without-pam \ --without-pgsql \ --without-sqlite \ --with-solr \ --with-bzlib \ --with-lz4 \ --with-ldap I get configure: error: cannot build with MySQL support: Neither MySQL (mysqlclient) nor MariaDB library (libmariadb) found. But I did install libldb-dev. I also installed libldap2-dev liblz4-dev But when I do: EXPAT_CFLAGS=/usr/include EXPAT_LIBS=/lib/x86_64-linux-gnu \ LZ4_CFLAGS=/usr/include LZ4_LIBS=/usr/lib/x86_64-linux-gnu \ ZLIB_CFLAGS=/usr/include ZLIB_LIBS=/lib/x86_64-linux-gnu \ MARIADB_LIBS=/usr/lib/x86_64-linux-gnu MARIADB_CFLAGS=/usr/include/mariadb \ ./configure \ --prefix=/usr/local/dovecot \ --with-sql \ --with-mysql \ --without-pam \ --without-pgsql \ --without-sqlite \ --with-solr \ --with-bzlib \ --with-lz4 It configures, them fails in the build. I got some LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* src, char* dest, int srcSize); I get a bunch of linker errors: /usr/bin/ld: ./.libs/libcompression.a(istream-lz4.o): in function `i_stream_lz4_read': /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-lz4.c:192:(.text+0x619): undefined reference to `LZ4_decompress_safe' /usr/bin/ld: ./.libs/libcompression.a(istream-zlib.o): in function `i_stream_zlib_init': /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:324:(.text+0x1d): undefined reference to `inflateInit2_' /usr/bin/ld: ./.libs/libcompression.a(istream-zlib.o): in function `i_stream_zlib_close': /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:46:(.text+0xa8): undefined reference to `inflateEnd' /usr/bin/ld: ./.libs/libcompression.a(istream-zlib.o): in function `i_stream_zlib_reset': /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:358:(.text+0x168): undefined reference to `inflateEnd' /usr/bin/ld: /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:358:(.text+0x3a7): undefined reference to `inflateEnd' /usr/bin/ld: ./.libs/libcompression.a(istream-zlib.o): in function `i_stream_zlib_read': /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:264:(.text+0x97f): undefined reference to `inflate' /usr/bin/ld: /usr/local/src/dovecot-2.4.2/src/lib-compression/istream-zlib.c:220:(.text+0xa7f): undefined reference to `inflateEnd' /usr/bin/ld: ./.libs/libcompression.a(ostream-lz4.o): in function `o_stream_lz4_compress': /usr/local/src/dovecot-2.4.2/src/lib-compression/ostream-lz4.c:94:(.text+0x12f): undefined reference to `LZ4_compress' /usr/bin/ld: ./.libs/libcompression.a(ostream-zlib.o): in function `o_stream_zlib_close': /usr/local/src/dovecot-2.4.2/src/lib-compression/ostream-zlib.c:91:(.text+0x1ee): undefined reference to `deflateEnd' /usr/bin/ld: ./.libs/libcompression.a(ostream-zlib.o): in function `o_stream_create_zlib': /usr/local/src/dovecot-2.4.2/src/lib-compression/ostream-zlib.c:412:(.text+0x339): undefined reference to `deflateInit2_' /usr/bin/ld: ./.libs/libcompression.a(ostream-zlib.o): in function `o_stream_zlib_send_flush': /usr/local/src/dovecot-2.4.2/src/lib-compression/ostream-zlib.c:281:(.text+0x577): undefined reference to `deflate' /usr/bin/ld: ./.libs/libcompression.a(ostream-zlib.o): in function `o_stream_zlib_send_chunk': /usr/local/src/dovecot-2.4.2/src/lib-compression/ostream-zlib.c:213:(.text+0x83b): undefined reference to `deflate' Any suggestions? Thanks. -- William G. Silverstein, Esq. 8383 Wilshire Blvd. Suite 630. Beverly Hills, CA 90211

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Error: userdb: client doesn't have lookup permissions for this user
by vwoloszczuk＠tutanota.com 09 Jan '26

09 Jan '26

Hi, I am trying to configure Dovecot 2.4.2 to work as MDA for Postfix 3.10.5, using LMTP and SASL, with virtual users. This is Debian 13. I had Postfix working fine before trying to incorporate Dovecot, and I was also able to get LMTP working with system users (no SASL), but now things are not working. I've followed the guides in the documentation for using Dovecot and Postfix, in particular the following page: https://doc.dovecot.org/2.4.2/howto/sasl/postfix.html I've set up my 'service auth {}' to look like in that page. When I send mail to <user>, I get the following logs and the message is deferred by Postfix: lmtp(119643): Connect from local auth(<user>): Error: userdb: client doesn't have lookup permissions for this user: userdb reply doesn't contain uid (to bypass this check, set: service auth { unix_listener /run/dovecot/auth-userdb { mode=0777 } }) lmtp(<user> <mailto:viktor@woloszcz.uk>)<119643><SRJICIBlYGlb0wEAk6KCeQ>: Error: auth-master: userdb lookup(<user>): Auth USER lookup failed lmtp(119643): Error: lmtp-server: conn unix:pid=119900,uid=101 [3]: rcpt <user>: Failed to lookup user <user>: Internal error occurred. Refer to server log for more information. lmtp(119643): Disconnect from local: Logged out (state=READY) I am using passwd-file passdb '/etc/dovecot/passwd' with entries in the form '<user>:{PLAIN}password'. This file is owned by root and is world-readable.I am not using a userdb but have set 'mail_uid = vmail' and 'mail_gid = vmail' The socket is located at '/var/spool/postfix/dovecot/auth' (i.e. visible to Postfix) and is owned by the postfix user.I've tried changing the permissions of the socket as the error message instructed but this didn't have any effect. I haven't set 'user = doveauth' as in this page:https://doc.dovecot.org/2.4.2/howto/virtual/postfix.html I don't understand what that would do. Please find attached my full dovecot.conf in case it is useful. Thanks in advance, Viktor Hi, I am trying to configure Dovecot 2.4.2 to work as MDA for Postfix 3.10.5, using LMTP and SASL, with virtual users. This is Debian 13. I had Postfix working fine before trying to incorporate Dovecot, and I was also able to get LMTP working with system users (no SASL), but now things are not working. I've followed the guides in the documentation for using Dovecot and Postfix, in particular the following page: [1]https://doc.dovecot.org/2.4.2/howto/sasl/postfix.html I've set up my 'service auth {}' to look like in that page. When I send mail to <user>, I get the following logs and the message is deferred by Postfix: lmtp(119643): Connect from local auth(<user>): Error: userdb: client doesn't have lookup permissions for this user: userdb reply doesn't contain uid (to bypass this check, set: service auth { unix_listener /run/dovecot/auth-userdb { mode=0777 } }) lmtp([2]<user>)<119643><SRJICIBlYGlb0wEAk6KCeQ>: Error: auth-master: userdb lookup(<user>): Auth USER lookup failed lmtp(119643): Error: lmtp-server: conn unix:pid=119900,uid=101 [3]: rcpt <user>: Failed to lookup user <user>: Internal error occurred. Refer to server log for more information. lmtp(119643): Disconnect from local: Logged out (state=READY) I am using passwd-file passdb '/etc/dovecot/passwd' with entries in the form '<user>:{PLAIN}password'. This file is owned by root and is world-readable. I am not using a userdb but have set 'mail_uid = vmail' and 'mail_gid = vmail' The socket is located at '/var/spool/postfix/dovecot/auth' (i.e. visible to Postfix) and is owned by the postfix user. I've tried changing the permissions of the socket as the error message instructed but this didn't have any effect. I haven't set 'user = doveauth' as in this page: [3]https://doc.dovecot.org/2.4.2/howto/virtual/postfix.html I don't understand what that would do. Please find attached my full dovecot.conf in case it is useful. Thanks in advance, Viktor References Visible links 1. https://doc.dovecot.org/2.4.2/howto/sasl/postfix.html 2. mailto:viktor@woloszcz.uk 3. https://doc.dovecot.org/2.4.2/howto/virtual/postfix.html

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how to use dovecot-lda with dovecot.crt?
by Matthias Bodenbinder 09 Jan '26

09 Jan '26

Hi, I have a self signed certificate for dovecot: > [root@rakete] /etc/dovecot > # ll > insgesamt 12K > -rwxr-xr-x 1 root root 1,7K 2026-01-09@09:56 dovecot.conf > -rw-r----- 1 root root 1,4K 2026-01-09@09:54 dovecot.crt > -rw-r----- 1 root root 1,7K 2026-01-09@09:54 dovecot.key in dovecot.conf I have: ssl_server { cert_file = /etc/dovecot/dovecot.crt key_file = /etc/dovecot/dovecot.key } This works fine for the evolution email client. But when I want to use dovecot-lda as part of my getmail6 config I get a permission denied: # getmail --rcfile dogado-rc -n -v getmail version 6.19.10 Copyright (C) 1998-2025 Charles Cazabon and others. Licensed under GPL-2.0. SimpleIMAPSSLRetriever:bodenbinder_de_9@imap.dogado.net:993: Delivery error (command dovecot-lda 1510042 error (89, doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 51: cert_file: open(/etc/dovecot/dovecot.crt) failed: Permission denied)) [INBOX] msg 1/1 (1392 bytes), delivery error (command dovecot-lda 1510042 error (89, doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 51: cert_file: open(/etc/dovecot/dovecot.crt) failed: Permission denied)) 1 messages (1392 bytes) retrieved, 0 skipped dogado-rc has this delivery section: [destination] type = MDA_external path = /usr/lib/dovecot/dovecot-lda arguments = ("-d", "matthias") When I change ownership of the certificate files it works: # chown root:matthias /etc/dovecot/dovecot.crt /etc/dovecot/dovecot.key [root@rakete] /etc/dovecot # ll /etc/dovecot/dovecot.crt /etc/dovecot/dovecot.key -rw-r----- 1 root matthias 1,4K 2026-01-09@09:54 /etc/dovecot/dovecot.crt -rw-r----- 1 root matthias 1,7K 2026-01-09@09:54 /etc/dovecot/dovecot.key If I do not change permissions for dovecot.key I get a similar error for that file too. But can this be the solution? That would mean that I need to give read access to the crt/key file to every user who wants to use dovecot-lda. Is that correct? Matthias

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YESCRYPT_COST_FACTOR=11 not working
by Matthias Bodenbinder 09 Jan '26

09 Jan '26

Hi, dovecot does not work with ENCRYPT_METHOD YESCRYPT and YESCRYPT_COST_FACTOR=11. I have tested with 2.4.2-4 and 2.3.21.1-4 on endeavouros. When changing YESCRYPT_COST_FACTOR to 11 in /etc/login.defs and recreacting the user password for my user and restarting the dovecot service I get: # doveadm auth test matthias Password: passdb: matthias auth failed extra fields: user=matthias When reverting the change to YESCRYPT_COST_FACTOR=5 it works again: # doveadm auth test matthias Password: passdb: matthias auth succeeded extra fields: user=matthias I have tested this back and forth. The culprit is definitely a high value for YESCRYPT_COST_FACTOR. A value of 7 is still good but a value of 9 or 11 fails. Matthias

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Republish of dovecot 2.4.2 packages
by Aki Tuomi 08 Jan '26

08 Jan '26

Hi! Due to mistake in RHEL 10 packaging, we have republished packages for 2.4.2. Content is still the same, build number has increased by one. The important change is that there is now pigeonhole package for RHEL 10. You can find the packages at https://repo.dovecot.org/ as usual. Kind regards, Aki Tuomi

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File system errors
by Jyrki Partanen 07 Jan '26

07 Jan '26

I am trying to move from one VPS to another and strange (for me) file system errors arose. On the new VPS the IMAP client can see the Inbox, but not any other mailboxes. I get these errors in the log: Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: open(/home/jyrki/mail/.imap/dovecot.list.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/dovecot.list.index.log stat(/home/jyrki/mail/.imap/dovecot.list.index.log) failed: Permission denied) Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: Mailbox INBOX: open(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/INBOX/dovecot.index.log stat(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied) Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: Couldn't create mailbox list lock /home/jyrki/mail/.imap/mailboxes.lock: file_create_locked(/home/jyrki/mail/.imap/mailboxes.lock) failed: safe_mkstemp(/home/jyrki/mail/.imap/mailboxes.lock) failed: Permission denied Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145499><nxbBGptHoMtVnMi0>: Error: Mailbox INBOX: open(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/INBOX/dovecot.index.log stat(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied) ...etc... The thing is that the permissions should be OK, the files are not "missing +r perm". Any idea how to fix this? Thanks! I am trying to move from one VPS to another and strange (for me) file system errors arose. On the new VPS the IMAP client can see the Inbox, but not any other mailboxes. I get these errors in the log: Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: open(/home/jyrki/mail/.imap/dovecot.list.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/dovecot.list.index.log stat(/home/jyrki/mail/.imap/dovecot.list.index.log) failed: Permission denied) Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: Mailbox INBOX: open(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/INBOX/dovecot.index.log stat(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied) Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145495><65K/GptHn8tVnMi0>: Error: Couldn't create mailbox list lock /home/jyrki/mail/.imap/mailboxes.lock: file_create_locked(/home/jyrki/mail/.imap/mailboxes.lock) failed: safe_mkstemp(/home/jyrki/mail/.imap/mailboxes.lock) failed: Permission denied Jan 5 04:49:14 partanen dovecot[144921]: imap(jyrki)<145499><nxbBGptHoMtVnMi0>: Error: Mailbox INBOX: open(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied (euid=1000(jyrki) egid=1000(jyrki) missing +r perm: /home/jyrki/mail/.imap/INBOX/dovecot.index.log stat(/home/jyrki/mail/.imap/INBOX/dovecot.index.log) failed: Permission denied) ...etc... The thing is that the permissions should be OK, the files are not "missing +r perm". Any idea how to fix this? Thanks!

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Non Existent User Login Attempts
by Bryan Simmons 07 Jan '26

07 Jan '26

Log contains several messages from dovecot that are not clear to me exactly what is occurring, single example below. These appear to be login attempts for the same group of non existent user ids from various rip addresses. Am I interpreting these correctly and, if so, is there any issue with just ignoring them? dovecot: pop3-login: Disconnected: Connection closed (auth failed, 1 attempts in 0 secs): user=<non-existent-user(a)example.net>, rip=0.0.0.0 Thank you, Bryan

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