February 2015 - dovecot

Postfix , Dovecot & the Spam fight
by Leander Schäfer 09 Feb '15

09 Feb '15

Hi, I'm currently busy with a substiution of my current mail server. I'm currently using * Clam-SMTP and * SpamAssassin to fight Spam. I wonder if it is worth implementing AmaViS with SpamAssassin backend instead and also using AmaViS to speak to clamd directly. But I more and more wonder wether AmaViS is even worth it?! It currently looks to me as if AmaViS is eating LOTS of ressources and it is very uncomfortable for automated installations if you have to do dynamic batch changes on the AmaViS configs - sed(1) is your friend but this hectic escaping and workarrounds is really not sustainable to maintain. So my question is: Does AmaViS have any advantages compared to the current setup? I don't seem to find lots of qualified discussions for this on the net. The AmaViS related articles I found are freaking old. Would be nice the get your best practice as a change. Thanks a lot Best regards Leander

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ssl_cipher_list
by LuKreme 08 Feb '15

08 Feb '15

How do I get a list of the possible ciphers that are installed on the system for use in ssl_cipher_list? -- They all have husbands and wives and children and houses and dogs, and you know, they've all made themselves a part of something and they can talk about what they do. What am I gonna say? "I killed the president of Paraguay with a fork. How've you been?"

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TLS config check
by SW 07 Feb '15

07 Feb '15

Hi All First the essentials: dovecot --version: 2.2.15 /usr/local/etc/dovecot/conf.d/10-ssl.conf: ssl = required ssl_cert = </usr/local/openssl/certs/mail.domain.com.chained.dovecot.ecdsa.crt ssl_key = </usr/local/openssl/certs/mail.domain.com.ecdsa.key ssl_protocols = !SSLv2 !SSLv3 ssl_cipher_list = HIGH:EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:EDH+aRSA:ECDHE-RSA-AES256-SHA:+DHE-RSA-AES256-SHA:!AES256-SHA256:!AES256-GCM-SHA384:!CAMELLIA256-SHA:!AES128:!CAMELLIA128:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!RC4:!SEED:+AES256-SHA ssl_prefer_server_ciphers = yes I would really appreciate it if someone could tell me if my config is super secure? I run the following email clients: K9 on Android 4.4.2 Thunderbird 31.4 Outlook 2010 I'm interested to know if the config I have is secure and that my cipher list is acceptable. I'm also keen to hear thoughts on my config in respect of Forward Secrecy and the SSLv3/POODLE attack. Thanks!

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Re: Interface for managing users?
by Thomas Moulia 06 Feb '15

06 Feb '15

Hello, > It's actually the way around: pick any user management and configure > Dovecot to use its database. > Depending on what you want, you need a system, that also removes the > user's home dirs and/or creates them from a skeleton. Makes sense, and is nicely simple. > After doing a change in the user database, make sure to run > doveadm auth cache flush > to force Dovecot to pick up the changes, before you fire up the next test. Ah, good to know -- that would've bit me. Thanks for the help, Steffen! -Thomas

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doveadm quota get doesn't recalculate quota (Maildir backend)
by Teodor Milkov 06 Feb '15

06 Feb '15

Hello, I've noticed that "doveadm quota get" doesn't recalculate quota if maildirsize file is missing for some reason. It just says quota is unknown, usage is 0. In contrast, vpopmail does regenerate maildirsize if it is missing. Reading the Maildir++ specification there is this part: ...If maildirsize does not exist, or if its size is at least 5120 bytes, recalculate it using the procedure defined above, and use the recalculated numbers... One seemingly legitimate reason for maildirsize to be missing is when vpopmail mailbox is set to NOQUOTA (i.e. no limits). My workaround to this is to use a fallback quota: quota_rule = ?:messages=10000000 That is, if there's no backend limit detected (missing maildirsize) then fallback to 10 mln message count quota. In this case doveadm quota get _does_ recalculate usage and even creates maildirsize file. So, my questions are: 1. Isn't it still better to calculate and show usage even if maildirsize is missing? Because calling quota recalc and then quota get is racy - someone else may change configuration or usage etc. between our two calls (forks). 2. If there's good reason against implicit recalculation, then maybe quota get output should be more specific that neither quota nor usage are known? Instead of usage=0 show -1 or "-" or "n/a" or "unkown"?

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Resubmission after N days
by Thomas Güttler 06 Feb '15

06 Feb '15

Hi, I would like to implement a 43Folder system[1] with dovecot and a mail user agent. Use case: - I have a new mail in my inbox. I read it and see that I can't handle it now. I want to handle this mail in 5 days. - Now I want to have some sort of resubmission: the mail should be moved to a different location for these 5 days. - After 5 days the mail should be moved to my inbox again. How can this be done with Dovecot/IMAP? I have programming experience, but I am new to Dovecot/IMAP. I would like solve this with Dovecot only (without a database or web server). Does the IMAP protocol over methods which could help? [1] 43Folder https://en.wikipedia.org/wiki/Tickler_file -- http://www.thomas-guettler.de/

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dsync and smooth conversion of Maildir to mdbox
by Sven Strickroth 06 Feb '15

06 Feb '15

Hi, I was experimenting with dsync for Maildir to mdbox conversion. Two isses arised there: * "subscriptions" only contained subscriptions of that namespace, all others were lost - Is there any configuration missing on my side? * "dovecot-acl-list" and "dovecot-acl" shares/permissions were not synced; UPDATE: if I also add "acl" to "mail_plugins" when running dsync (using -o mail_plugins="acl zlib") it works, however, all documentation, e.g. the wiki2, only mention to add acl to lmtp/lda and imap services. - Is there any problem adding acl to "global" mail_plugins? Regarding shared namespace: I cannot convert all mailboxes at once and have to do it mailbox after mailbox. The setting "location = maildir:%%h/Maildir" won't work as some mailboxes are already converted and others aren't. Is there a way to cope with that? "doveconf -n" outout: # 2.2.13: /etc/dovecot/dovecot.conf # OS: Linux 3.16-0.bpo.3-amd64 x86_64 Debian 7.8 dict { acldict = mysql:/etc/dovecot/dovecot-dict-user_shares.conf quotadict = mysql:/etc/dovecot/dovecot-dict-quota.conf } mail_gid = 8 mail_location = maildir:%h/Maildir mail_plugins = quota zlib mail_privileged_group = mail mail_shared_explicit_inbox = yes mail_uid = 999 namespace { list = children location = maildir:%%h/Maildir prefix = shared/%%u/ separator = / subscriptions = no type = shared } namespace inbox { inbox = yes list = yes location = prefix = separator = / subscriptions = yes type = private } passdb { args = /etc/dovecot/79p-sql.conf driver = sql } plugin { acl = vfile acl_anyone = allow acl_shared_dict = proxy::acldict quota = dict:user::proxy::quotadict quota_grace = 0 quota_rule2 = Trash:bytes=+100M } protocols = " imap lmtp" service auth { unix_listener auth-userdb { group = mail mode = 0660 user = vmail } } service dict { unix_listener dict { group = mail mode = 0660 user = vmail } } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { mode = 0600 user = postfix } user = vmail } userdb { driver = prefetch } userdb { args = /etc/dovecot/79p-sql.conf driver = sql } -- Best regards, Sven Strickroth PGP key id F5A9D4C4 @ any key-server

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Interface for managing users?
by Thomas Moulia 06 Feb '15

06 Feb '15

Hey all, I'd like to use dovecot as an testing/benchmarking IMAP server for switchboard (https://github.com/thusfresh/switchboard) As part of the tests, I need to add and destroy dovecot users. Is there an interface or tool for this sort of user management at a higher-level than editing the user store, e.g. passwd-file, sql, ...? Also, more generally, are there any tools for using dovecot to test against? Thanks! -Thomas

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dovecot.index.log in Maildir/cur
by George Sexton 06 Feb '15

06 Feb '15

I'm seeing two bogus messages appearing my Maildir/cur directory. They're dovecot.index.log and dovecot-uidlist. -rw------- 1 gsexton users 51 Feb 4 09:04 Maildir/cur/dovecot-uidlist:2,S -rw------- 1 gsexton users 244 Feb 4 09:04 Maildir/cur/dovecot.index.log These files are only appearing in the Maildir/cur directory, and not in any other directory that mail is delivered to (e.g. mail list directories). I'm using the current version of Mozilla Thunderbird as my mail client. Mail is delivered to Maildir/ by procmail. I was originally using Courier, but changed to dovecot. I did run the conversion program on all the mail boxes. Other than these If anyone could help me understand what I'm doing wrong, I'd appreciate it. I've researched the mail list and read the wiki articles, but I'm just not seeing anything that looks helpful. Here's my config info: # 2.2.13: /etc/dovecot/dovecot.conf # OS: Linux 3.16.7-7-default x86_64 openSUSE 13.2 (x86_64) -> File System: btrfs mail_location = maildir:~/Maildir managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = INBOX. separator = . } passdb { driver = pam } plugin { sieve = ~/.dovecot.sieve sieve_dir = ~/sieve } protocols = imap service imap-login { inet_listener imaps { port = 993 ssl = yes } } ssl = required ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem ssl_key_password = ************ ssl_protocols = !SSLv2 !SSLv3 userdb { driver = passwd } protocol imap { mail_max_userip_connections = 20 } -- George Sexton *MH Software, Inc.* Voice: 303 438 9585 http://www.mhsoftware.com

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Re: Re: auth: Warning: DNS lookup took 1.550 s
by Joseph Tam 06 Feb '15

06 Feb '15

ML mail writes: > My fault here, I should have precised that the DNS query it tries to > resolve is simply the DNS name of my mailbox server > (mailboxserver.domain.com) So domain.com is hosted locally on DNS > servers on that very same network as the dovecot servers are located. > Furthermore all the resolvers I use in /etc/resolv.conf are also local > DNS resolvers on that same LAN. All the DNS servers (authoritative and > recursive) are using PowerDNS. That's why I was really puzzled to see > that it can take up to 1.5 seconds to query my own local DNS servers > which are in no way overloaded. That really doesn't change my answer, but since you control the entire DNS chain of query and response, you can further debug it at the server end via logs or network tracing. And you should still run a comprehesive DNS trace (e.g. http://dns.squish.net/) since a misconfiguration could still cause your DNS resolver to go on wild goose chases. In either case, it's probably not Dovecot related. If you want to triage it, just enter static entries into your proxy's /etc/hosts file. Or use bare IPs in your configurations. Joseph Tam <jtam.home(a)gmail.com>

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