Delays in mail deliveries

[Nikolaos Milas]

On 2/3/2022 6:17 μ.μ., Bastian Blank wrote:

> This queue id line is from a Postfix, it is not from a Dovecot!  You
> need to show logs from vmail2.noa.gr.  And that 300 delay sounds like a
> timeout.
>
> Do you actually know your setup?  Or are you guessing?

Hi Bastian,

Although I cannot claim high expertise, I do know (hopefully well 
enough) my setup! :)

So, the end server (vmail2) runs postfix and dovecot.

However, all the logs I have posted are from the gateway server 
(mailgw1) and are indeed postfix and amavis only.

Postfix (at mailgw1.noa.gr) receives mail from the internet, it forwards 
it to amavis (localhost:10024), then amavis forwards it back to postfix 
(localhost:127.0.0.1:10025) which eventually delivers to vmail2.noa.gr.

So the logs I posted are from these three phases.

Here are the associated listeners (postfix is listening at port 25 via 
postscreen):

tcp        0      0 0.0.0.0:25              0.0.0.0:*               
LISTEN 1257592/postscreen
tcp        0      0 127.0.0.1:10024 0.0.0.0:*               LISTEN      
1064531/amavisd (ma
tcp        0      0 127.0.0.1:10025 0.0.0.0:*               LISTEN      
1257631/smtpd
tcp6       0      0 :::25 :::*                    LISTEN      
1257592/postscreen
tcp6       0      0 ::1:10024 :::*                    LISTEN      
1064531/amavisd (ma

And postfix master.cf:

============================================================================================
# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (yes)   (never) (100)
# ==========================================================================
#smtp      inet  n       -       n       -       -       smtpd -v
smtp      inet  n       -       n       -       1 postscreen
smtpd     pass  -       -       n       -       -       smtpd
dnsblog   unix  -       -       n       -       0       dnsblog
tlsproxy  unix  -       -       n       -       0       tlsproxy
#submission inet n       -       n       -       -       smtpd
#  -o smtpd_enforce_tls=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#smtps     inet  n       -       n       -       -       smtpd
#  -o smtpd_tls_wrappermode=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#628      inet  n       -       n       -       -       qmqpd
pickup    fifo  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      fifo  n       -       n       300     1       qmgr
#qmgr     fifo  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       - trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
smtp      unix  -       -       n       -       -       smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
         -o smtp_fallback_relay=
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       n       -       -       showq
error     unix  -       -       n       -       -       error
discard   unix  -       -       n       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
scache    unix  -       -       n       -       1       scache
retry     unix  -       -       n       -       -       error
proxywrite unix -       -       n       -       1       proxymap

smtp-amavis unix -      -       n       -       2       lmtp
     -o smtp_data_done_timeout=1200
     -o smtp_send_xforward_command=yes
     -o disable_dns_lookups=yes
     -o max_use=20

127.0.0.1:10025 inet n  -       n -       -       smtpd
     -o content_filter=
     -o local_recipient_maps=
     -o relay_recipient_maps=
     -o smtpd_restriction_classes=
     -o smtpd_delay_reject=no
     -o smtpd_client_restrictions=permit_mynetworks,reject
     -o smtpd_helo_restrictions=
     -o smtpd_sender_restrictions=
     -o smtpd_recipient_restrictions=permit_mynetworks,reject
     -o smtpd_data_restrictions=reject_unauth_pipelining
     -o smtpd_end_of_data_restrictions=
     -o mynetworks=127.0.0.0/8
     -o smtpd_error_sleep_time=0
     -o smtpd_soft_error_limit=1001
     -o smtpd_hard_error_limit=1000
     -o smtpd_client_connection_count_limit=0
     -o smtpd_client_connection_rate_limit=0
     -o 
receive_override_options=no_header_body_checks,no_unknown_recipient_checks,no_milters
============================================================================================

Cheers,
Nick