Archiving and number of licensed accounts

[maria.w]

We have a client with a single-server zimbra solution hosted on a Mac OS X server (v5.0.18_GA_3011.MACOSXx86). Archiving has suddenly stopped working - no new messages are copied to the archive accounts. I find no errors in zimbra.log or the mailbox.log referencing the archived accounts. I do see that, however, the number of accounts on the machine exceeds the total licensed account number.

Does exceeding the license count 'disable' archiving?

If this problem is not related to exceeding the license, where else could I look to decipher why archiving has ceased to function?

M