IBM Domino 9.0.1FP4 HF523, IBM Notes 9.0.1FP5

We have a problem receiving incoming SMTP e-mails from a particular (external) sender that's only recently started, in that all formatting is stripped out of the message and arriving as plain text.

Looking at the page source in the Notes client there's only one MIME part, which contains just the bare text as displayed... no additional HTML parts or file attachments.

However if I enable saving of the incoming SMTP stream at the server with set config SMTPSaveImportErrors=2 and look at the resultant text file, there's an additional MIME part with a winmail.dat file attachment.

Decoding this raw text and running it through a winmail.dat decoder reveals the original e-mail with all formatting intact!

Nothing has been changed to our server version or configuration recently, and although I'm unable to say the same for the sending server, the raw source of the message (presumably before Domino's tried any conversions) suggests the Domino SMTP server is screwing something up. It's as if it tries to convert winmail.dat, has a problem, then bins the attachment entirely.

Any thoughts?

1 Answer 1


If other external domains are sending email to you where winmail.dat is being processed successfully by Domino, then it's a sending-side issue. If this is the case, then a good test would be the following: have a different user from the same external organization send an email to you and see if the winmail.dat gets stripped or if it makes it intact. If it's domain-wide from the external, contact their mail admins. If it's just the single user, have them remove your internal user's contact information from their Outlook client, re-add, and try sending again.

  • 1
    Thanks @vigilem - all e-mails from this particular organisation exhibit the same problem, so it does suggest an issue at their end. I suspect that MS has tweaked the format of the TNEF wrapper with a recent update, which the Domino converter is baulking at.... which is the very reason why Exchange admins shouldn't be permitting it to be used for external e-mail :-/
    – dmulv
    Feb 16, 2016 at 9:12

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