sendmail duplicate messages

[furejuvo]

If the server has a high load (above 12) messages will be kept on a fallback mailserver (also sendmail). However, as soon as the server is accepting messages again some of the messages of the fallback mailserver get sent twice or even more times with according to the complete mail headers the same message-id, same sendmail process id of the fallback server, but a different sendmail process id of the main server.

I have increased time-outs, but that doesn't seem to solve the problem.

Thanks for your suggestions,

Tsjêbbe de Vries
Stichting Antenna
The Netherlands