Mail was delivered after two months

[Stefan Fricke]

Hello,

I'm running a small mailserver with some 500 mails per day. On the same 
machine is running Postfis as mail server and a web server. Now a mail 
generated by a web application was sent to an cyrus account on this machine. 
According to the headers it was handed over from Postfix to Cyrus on 13th 
June. Now the recipient claims that he has got the mail yesterday though he 
is checking his mail frequently. This I can confirm from the log files.

But why did this happen? Where was the mail stored during these two months? 
Why was it delivered just yesterday? How can I avoid this this happens again? 
I didn't find any information about this in the log files. 

So what can I do now?

The version is Cyrus 2.2.12 running on Suse Linux 9.3.