Summary
You see the following error message in the mai logs of HES:
Timed out while sending end of data -- message may be sent more than once.
If the mail log contains this message, you may encounter the following:
- You might receive emails from a specific domain.
- You will receive many repeat emails.
Details
These are compatibility issues with Postfix caused by the smtp fixup or CISCO SMTP/ESMTP inspection of old CISCO ASA version. CISCO SMTP/ESMTP inspection is very strict with RFC compliance and can cause issues when you use Exchange 2007 servers, which may not be very strict with RFC compliance.
To resolve the issue:
- Download Cisco ASA 5500 Series Release Notes Version 8.0(4).
- Disable the SMTP and ESMTP inspection in ASA by running the following commands:
- policy-map global_policy
- class INSPECTION_DEFAULT
- no inspect esmtp
- no inspect smtp
To ASA firewall administrators, you may disable SMTP/ESMTP inspection in CISCO ASA because it is very stable and works well.
