Hi, does anyone have any tips or recommendations on my question involving support for the new Outlook?

How do I configure dovecot to support both "username" and " username@mydomain.com"?

Thanks, Alex

On Mon, Aug 4, 2025 at 12:18 PM Alex <mysqlstudent@gmail.com> wrote:

Hi, I'm using dovecot-2.3.21 on fedora40 and have configured it to use only usernames without domain when logging in.

Now apparently the new Outlook (1.2025.617.000) no longer supports the ability to change username for IMAP. Now what?

We have other users who are using older versions of Outlook and Thunderbird and webmail that still support this login method. How can I support both?

Here is my dovecot info.

2.3.21.1 (d492236fa0): /etc/dovecot/dovecot.conf

OS: Linux 6.12.6-100.fc40.x86_64 x86_64 Fedora release 40 (Forty) btrfs

auth_mechanisms = plain login default_client_limit = 3000 default_process_limit = 4000 default_vsz_limit = 1 G dict { sql = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext } disable_plaintext_auth = no lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes listen = 209.216.XXX.60, 127.0.0.1 mail_gid = users mail_location = maildir:/home/%u/Maildir mail_max_userip_connections = 100 mail_plugins = " listescape last_login" mail_privileged_group = mail 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 = } passdb { driver = pam } plugin { last_login_dict = proxy::sql last_login_key = # hidden, use -P to show it last_login_precision = ms sieve = ~/.dovecot.sieve sieve_dir = ~/sieve } protocols = pop3 imap lmtp service anvil { client_limit = 12003 } service auth-worker { client_limit = 20000 } service auth { client_limit = 20000 unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } service imap-login { inet_listener imaps { port = 993 ssl = yes } process_min_avail = 20 service_count = 0 vsz_limit = 1 G } service lmtp { executable = lmtp -L inet_listener lmtp { address = 127.0.0.1 port = 24 } process_min_avail = 5 unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } ssl_ca = </var/www/example.com-443/ssl/DigiCertCA-2022.crt ssl_cert = </var/www/example.com-443/ssl/example-combined-2025.crt ssl_key = # hidden, use -P to show it userdb { driver = passwd } protocol lda { info_log_path = /var/log/dovecot-lda.log log_path = /var/log/dovecot-lda-errors.log } protocol imap { mail_max_userip_connections = 100 } protocol pop3 { pop3_uidl_format = %08Xu%08Xv } local_name example.com { ssl_cert = </var/www/example.com-443/ssl/example-combined-2025.crt ssl_key = # hidden, use -P to show it } local_name users.example1.com { ssl_cert = </etc/letsencrypt/example1-fullchain.pem ssl_key = # hidden, use -P to show it }

We're also using postfix to support this basic sasl username when sending.

smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_auth_enable = yes smtpd_sasl_local_domain = $myhostname broken_sasl_auth_clients = yes smtpd_sasl_authenticated_header = yes smtpd_sasl_security_options = noanonymous, noplaintext smtpd_sasl_tls_security_options = noanonymous

Hi, does anyone have any tips or recommendations on my question involving support for the new Outlook?

How do I configure dovecot to support both "username" and "[1]username@mydomain.com"? Thanks, Alex On Mon, Aug 4, 2025 at 12:18PM Alex <[2]mysqlstudent@gmail.com> wrote:

 Hi, I'm using dovecot-2.3.21 on fedora40 and have configured it to use
 only usernames without domain when logging in.
 Now apparently the new Outlook (1.2025.617.000) no longer supports the
 ability to change username for IMAP. Now what?
 We have other users who are using older versions of Outlook and
 Thunderbird and webmail that still support this login method. How can I
 support both?
 Here is my dovecot info.
 # 2.3.21.1 (d492236fa0): /etc/dovecot/dovecot.conf
 # OS: Linux 6.12.6-100.fc40.x86_64 x86_64 Fedora release 40 (Forty)
 btrfs
 auth_mechanisms = plain login
 default_client_limit = 3000
 default_process_limit = 4000
 default_vsz_limit = 1 G
 dict {
   sql = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
 }
 disable_plaintext_auth = no
 lda_mailbox_autocreate = yes
 lda_mailbox_autosubscribe = yes
 listen = 209.216.XXX.60, 127.0.0.1
 mail_gid = users
 mail_location = maildir:/home/%u/Maildir
 mail_max_userip_connections = 100
 mail_plugins = " listescape last_login"
 mail_privileged_group = mail
 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 =
 }
 passdb {
   driver = pam
 }
 plugin {
   last_login_dict = proxy::sql
   last_login_key = # hidden, use -P to show it
   last_login_precision = ms
   sieve = ~/.dovecot.sieve
   sieve_dir = ~/sieve
 }
 protocols = pop3 imap lmtp
 service anvil {
   client_limit = 12003
 }
 service auth-worker {
   client_limit = 20000
 }
 service auth {
   client_limit = 20000
   unix_listener /var/spool/postfix/private/auth {
     group = postfix
     mode = 0660
     user = postfix
   }
 }
 service imap-login {
   inet_listener imaps {
     port = 993
     ssl = yes
   }
   process_min_avail = 20
   service_count = 0
   vsz_limit = 1 G
 }
 service lmtp {
   executable = lmtp -L
   inet_listener lmtp {
     address = 127.0.0.1
     port = 24
   }
   process_min_avail = 5
   unix_listener /var/spool/postfix/private/dovecot-lmtp {
     group = postfix
     mode = 0600
     user = postfix
   }
 }
 ssl_ca = </var/www/example.com-443/ssl/DigiCertCA-2022.crt
 ssl_cert = </var/www/example.com-443/ssl/example-combined-2025.crt
 ssl_key = # hidden, use -P to show it
 userdb {
   driver = passwd
 }
 protocol lda {
   info_log_path = /var/log/dovecot-lda.log
   log_path = /var/log/dovecot-lda-errors.log
 }
 protocol imap {
   mail_max_userip_connections = 100
 }
 protocol pop3 {
   pop3_uidl_format = %08Xu%08Xv
 }
 local_name [3]example.com {
   ssl_cert = </var/www/example.com-443/ssl/example-combined-2025.crt
   ssl_key = # hidden, use -P to show it
 }
 local_name [4]users.example1.com {
   ssl_cert = </etc/letsencrypt/example1-fullchain.pem
   ssl_key = # hidden, use -P to show it
 }
 We're also using postfix to support this basic sasl username when
 sending.
 smtpd_sasl_type = dovecot
 smtpd_sasl_path = private/auth
 smtpd_sasl_auth_enable = yes
 smtpd_sasl_local_domain = $myhostname
 broken_sasl_auth_clients = yes
 smtpd_sasl_authenticated_header = yes
 smtpd_sasl_security_options = noanonymous, noplaintext
 smtpd_sasl_tls_security_options = noanonymous

References

Visible links

1. mailto:username@mydomain.com
2. mailto:mysqlstudent@gmail.com
3. http://example.com/
4. http://users.example1.com/

On 8/4/25 12:18, Alex via dovecot wrote:

Hi, I'm using dovecot-2.3.21 on fedora40 and have configured it to use
only usernames without domain when logging in.
Now apparently the new Outlook (1.2025.617.000) no longer supports the
ability to change username for IMAP. Now what?
We have other users who are using older versions of Outlook and
Thunderbird and webmail that still support this login method. How can I
support both?

Well you're already pretty much screwed using Outlook, so you will have much bigger problems than this to look forward to. However, 20+ years ago in the process of migrating away from username to username@domain logins in Dovecot, I set up a stored function in MySQL that takes care of this transparently. In the user_query and password_query configurations I query this function. It looks for the presence of '@' and applies a default domain name if it's not present.

This is in constant use here to this day, and it works great.

           -Dave

-- Dave McGuire, AK4HZ New Kensington, PA

On Mon, Aug 4, 2025 at 7:22 PM Alex via dovecot <dovecot@dovecot.org> wrote:

Hi, I'm using dovecot-2.3.21 on fedora40 and have configured it to use only usernames without domain when logging in. Now apparently the new Outlook (1.2025.617.000) no longer supports the ability to change username for IMAP. Now what?

To "change usernames for IMAP" - what do you mean by that? Usernames are static records.

We have other users who are using older versions of Outlook and

Thunderbird and webmail that still support this login method. How can I support both?

I also don't understand the question.

However, I do understand you need to support MuA's login with either johndoe or johndoe@domain.name. I have a solution for you, but it's based on MySQL/MariaDB. I use Exim (MTA), Dovecot (2.4.1), and SOGo (Groupware/Webmail). It's easy to use the same config with Dovecot 2.3.21. If you are interested, reach out offlist. It should be easy to get going.

-- Best regards, Odhiambo WASHINGTON, Nairobi,KE +254 7 3200 0004/+254 7 2274 3223 In an Internet failure case, the #1 suspect is a constant: DNS. "Oh, the cruft.", egrep -v '^$|^.*#' ¯\_(ツ)_/¯ :-) [How to ask smart questions: http://www.catb.org/~esr/faqs/smart-questions.html]

On Mon, Aug 4, 2025 at 7:22PM Alex via dovecot <[1]dovecot@dovecot.org> wrote:

    Hi, I'm using dovecot-2.3.21 on fedora40 and have configured it to
 use
    only usernames without domain when logging in.
    Now apparently the new Outlook (1.2025.617.000) no longer supports
 the
    ability to change username for IMAP. Now what?

To "change usernames for IMAP" - what do you mean by that? Usernames are static records.

    We have other users who are using older versions of Outlook and
    Thunderbird and webmail that still support this login method. How can
 I
    support both?

I also don't understand the question. However, I do understand you need to support MuA's login with either johndoe or [2]johndoe@domain.name. I have a solution for you, but it's based on MySQL/MariaDB. I use Exim (MTA), Dovecot (2.4.1), and SOGo (Groupware/Webmail). It's easy to use the same config with Dovecot 2.3.21. If you are interested, reach out offlist. It should be easy to get going.

-- Best regards, Odhiambo WASHINGTON, Nairobi,KE +254 7 3200 0004/+254 7 2274 3223 In an Internet failure case, the #1 suspect is a constant: DNS. "Oh, the cruft.", egrep -v '^$|^.*#' -\_(Tu)_/- :-) [How to ask smart questions: [3]http://www.catb.org/~esr/faqs/smart-questions.html]

References

Visible links

1. mailto:dovecot@dovecot.org
2. mailto:johndoe@domain.name
3. http://www.catb.org/~esr/faqs/smart-questions.html