Thanks for answering. The timeouts happened because postfix was waiting for opendkim. Changing the socket from tcp to unix domainsockets solved this, almost: at busy moments postfix now logs:
telemann postfix-13/smtpd[28087]: warning: connect to Milter service unix:/var/run/opendkim/opendkim.sock: Resource temporarily unavailable And opendkim says: opendkim[3963]: OpenDKIM Filter: accept() returned invalid socket (Numerical result out of range), try again Is postfix requesting something invalid, or is this a problem with opendkim? Thanks again. -- Sent from: http://postfix.1071664.n5.nabble.com/Postfix-Users-f2.html