When receiving and decrypting a 5MB email, the email is rejected and the error “ASN1 not enough memory” is displayed. The same error is also displayed in message tracking.
This problem occurs because a buffer size is not properly increased by the .NET framework. This problem is known to Microsoft and can be fixed with the hotfix below.
To resolve this problem, install the following Microsoft hotfix: http://support.microsoft.com/kb/2480994/de