Smtp Relay suddenly stopped sending mail

[1to1computersLtd]

Hi

I have zimbra 8.6 running on Ubuntu 16.04 which has been happy for the last several years but yesterday morning stopped sending any emails.

A look at the Zimbra admin console showed all the emails being deferred with "unknown mail transport error" and the mail.log showed all outgoing email as postfix/error and relay=none (whereas older logs showed relay="my.relay.server".)

All incoming emails are working fine.

I have done the following:

Checked that the smtp server is actually responding
Restarted zimbra
Checked smtp relay settings, all are fine
Removed smtp relay and re-setup
Used my not inconsiderable Google-Fu, to no avail

I cannot work out why zimbra refuses to send emails

Anybody have any ideas where I can look?

[DualBoot]

Hello,

relay with zimbra can have different values, it depends on the Postfix treatment destination (amavis, lmtp, smtp).
So relay could be equal to none, 127.0.0.1, your zimbra store hostname, a MX server .

Maybe you have set up an external relay host ?

Regards,

[1to1computersLtd]

Hi, Thanks for the Reply.

I have since changed the outgoing smtp relay server to smtp-relay.sendinblue.com:587.

I have correctly set up /opt/zimbra/conf/relay_password file with my server, username and password.
I have also set the following in accordance with Sendinblue Postfix recommendations:

smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = may
header_size_limit = 4096000
relayhost = smtp-relay.sendinblue.com:587
smtp_sasl_password_maps = lmdb:/opt/zimbra/conf/relay_password

Now I am getting the following errors in the mail.log:

Code: Select all

Jun 25 12:57:12 server postfix/smtp[23936]: error: unsupported dictionary type: hash
Jun 25 12:57:12 server postfix/smtp[23937]: error: unsupported dictionary type: hash
Jun 25 12:57:12 server postfix/smtp[23936]: warning: hash:/etc/zimbra_tls_policy is unavailable. unsupported dictionary type: hash
Jun 25 12:57:12 server postfix/smtp[23936]: warning: hash:/etc/zimbra_tls_policy lookup error for "smtp-relay.sendinblue.com:587"
Jun 25 12:57:12 server postfix/smtp[23936]: warning: smtp_tls_policy_maps, next-hop destination "smtp-relay.sendinblue.com:587": policy table lookup error
Jun 25 12:57:12 server postfix/smtp[23937]: warning: hash:/etc/zimbra_tls_policy is unavailable. unsupported dictionary type: hash
Jun 25 12:57:12 server postfix/smtp[23937]: warning: hash:/etc/zimbra_tls_policy lookup error for "smtp-relay.sendinblue.com:587"
Jun 25 12:57:12 server postfix/smtp[23937]: warning: smtp_tls_policy_maps, next-hop destination "smtp-relay.sendinblue.com:587": policy table lookup error
Jun 25 12:57:12 server postfix/qmgr[16722]: warning: private/smtp socket: malformed response
Jun 25 12:57:12 server postfix/qmgr[16722]: warning: transport smtp failure -- see a previous warning/fatal/panic logfile record for the problem description
Jun 25 12:57:12 server postfix/master[16720]: warning: process /opt/zimbra/postfix/libexec/smtp pid 23936 killed by signal 11
Jun 25 12:57:12 server postfix/master[16720]: warning: /opt/zimbra/postfix/libexec/smtp: bad command startup -- throttling

The only thing that seems a bit odd is the following as the old smtp relay used port 25 and the new one uses 587:

Code: Select all

zimbra@server:~$ grep -i smtp /etc/services
smtp            25/tcp          mail
urd             465/tcp         ssmtp smtps  # URL Rendesvous Directory for SSM
zimbra@server:~$ grep -i 587 /etc/services
submission      587/tcp                         # Submission [RFC4409]
submission      587/udp

[DualBoot]

Which Postfix did you modify ?
I do not understand.