Incoming E-Mails with Attachments Failed – “Message size exceeds fixed maximum message size”

In Nintex workflows, some of the alert emails were failed! Further investigation found this issue happens only on notification emails with attachments of 1 MB+.

Moreover, There was a event logged in Event Log: System.Net.Mail.SmtpException: Exceeded storage allocation. The server response was: 5.3.4 Message size exceeds fixed maximum message size.

System.Net.Mail.SmtpException: Exceeded storage allocation. The server response was: 5.3.4 Message size exceeds fixed maximum message size.

Checked the Exchange Server Message size limits, It was 20 MB but still unable to send mails with 2 MB! After a bit of googling, found the issue: SMTP Server settings.

Exceeded storage allocation SMTP Settings

After increasing the Message Size & Session Size, everything turned good.

Salaudeen Rajack

Salaudeen Rajack is a SharePoint Architect with Two decades of SharePoint Experience. He loves sharing his knowledge and experiences with the SharePoint community, through his real-world articles!

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