SAP Knowledge Base Article - Public

3216356 - SuccessFactors Outbound Email Size Limit with Attachments


  • Unable to receive some emails with attachments.
  • What is the outbound email size limit?


SAP SuccessFactors HXM Suite

Reproducing the Issue

  1. Sent an email with attachments;
  2. The email was sent successfully but the recipient failed to receive the email;
  3. Sent again with fewer attachments;
  4. The recipient received the email.


The current outbound email size limit is 20MB of data. However, when sending an email with attachments, the actual email size may be larger than expected, when processing through a Cisco Email Security Appliance.

This is an expected behavior due to the encoding as per confirmed by Cisco - Why are mail attachments bigger than the original file?.

        "Thus, the actual length of MIME-compliant base64-encoded binary data is usually about 137% of the original data length,
        though for very short messages the overhead can be a lot higher because of the overhead of the headers.
        Very roughly, the final size of base64-encoded binary data is equal to 1.37 times the original data size + 814 bytes (for headers)."

For example, when the original email size is 15MB, the actual email size will still exceed 20MB because 15MB times 1.37 + 814 bytes (=20.55MB roughly) is greater than 20MB.

(Information for SAP Support only)
Error log - "Mail sender final check: mail exceeds limit 20M. Email delivery failed."


Please send emails with lesser attachment size and ensure the ideal original email size less than 14MB.

See Also

Cisco Support FAQ - Why are mail attachments bigger than the original file?

As of 2H 2023 you can now monitor the delivery of email notifications using Stories in People Analytics. For more details see KBA 3387145 - Reporting on the delivery of System Email Notifications


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