Re: Supporting both "username" to username@domain.com

11 Aug 2025


      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 = &lt;/var/www/example.com-443/ssl/DigiCertCA-2022.crt
 ssl_cert = &lt;/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 = &lt;/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 = &lt;/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

mailto:username@mydomain.com
mailto:mysqlstudent@gmail.com
http://example.com/
http://users.example1.com/