postscreen_cache.db no such file | postfix forwarding delay

[hk@]

Hi
what we see quite frequently in the syslog:

May 29 12:44:47 mailgate postfix/postscreen[14110]: close database /var/lib/postfix/postscreen_cache.db: No such file or directory (possible Berkeley DB bug)

and could you please elaborate on the logistics on forwarding as we see the following:

proxmox MG try to check the destination email for existence (as configured), but due to wrong configuration at the destination mailserver it receives a 450 error and therefore denies to receive the email - this is perfectly fine.
after a few minutes the source server tries to deliver this email again, now proxmox MG responds using the cached 450 error response without contacting the destination server for a very long time.

Where could we either force proxmox/postfix to ask the destination again or how could we reduce the caching time for those responses?

thank you in advance,
hk

 

[dietmar]

First, you can ignore that warning.

The cache is stored in /var/lib/postfix/verify_cache.db. Simply delete the file to empty the cache (maybe restart postfix).

The address_verify_negative_refresh_time is set to 3 hours by default.

Also see

# man 8 verify

for a more detailed description