emltpl New OutLook (ver 16.113.2) mail missing attachment

Question

emltpl New OutLook (ver 16.113.2) mail missing attachment

Vinh Ngo 0

I'm using below code to create .emltpl New OutLook (ver 16.113.2) mail. But the attachment don't have in the compose windows when i open this file. My question is any problem with my code?

I'm using this code in FileMaker, this code worked perfeclty in ver 16.112.2

"X-Unsent: 1" & $CRLF &

"From: " & $emailfrom & $CRLF &

"To: " & $emailto & $CRLF &

"Cc: " & $emailcc & $CRLF &

"Subject: " & $subject & $CRLF &

"MIME-Version: 1.0" & $CRLF &

"Content-Type: multipart/mixed; boundary="" & $boundary & """ & $CRLF & $CRLF &

"--" & $boundary & $CRLF &

"Content-Type: text/html; charset="utf-8"" & $CRLF &

"Content-Transfer-Encoding: 8bit" & $CRLF & $CRLF &

$emailbody & $CRLF &

"--" & $boundary & $CRLF &

"Content-Type: application/pdf; name="" & $filename & """ & $CRLF &

"Content-Transfer-Encoding: base64" & $CRLF &

"Content-Disposition: attachment; filename="" & $filename & """ & $CRLF & $CRLF &

$pdfBase64 & $CRLF &

"--" & $boundary & "--" & $CRLF

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Answer 1

Chloe-V 13,460 Microsoft External Staff Moderator

Hi @Vinh Ngo

Since the same .emltpl file created by FileMaker displays the attachment correctly in Outlook version 16.112.2 but not in version 16.113.2, this issue may be related to a change in how the newer version parses MIME content.

Please ensure that each MIME boundary is written as --boundary, the closing boundary is written as --boundary--, and there is a blank line between the attachment headers and the Base64 content. Also, confirm that Content-Type: application/pdf; name="filename.pdf" and Content-Disposition: attachment; filename="filename.pdf" are both present, and that the Base64 data contains only the encoded PDF content.

If the MIME structure is valid and the issue occurs only in version 16.113.2, please contact Microsoft Support for further assistance.

Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.

Thank you for your understanding.

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Chloe-V 13,460 Reputation points Microsoft External Staff Moderator

2026-09-27T23:46:43.58+00:00

Hi @Vinh Ngo

May I know if you have got any chance to check my answer? I am glad to help if you have any other questions.
Vinh Ngo 0 Reputation points

2026-09-28T01:12:25.6733333+00:00

Hi Chloe-V,

I'm sorry I completely forgot to reply to you. I've checked the MIME structure in both versions 16.112.2 and 16.113.2 – there's no difference.

Even when I create the template (.emltpl) directly from New Outlook version 16.113.2 -> save as template and then double-click to reopen the template file, the attachment is still missing. I believe the problem might be that the new Outlook has limitations on local attachments?

However, I found a solution to this – by using a System event to send a keystroke and find the file path. Essentially, it solved my problem using a subscript.

Of course, it would be better if Outlook could attach files from .emltpl. I hope they can fix this bug or provide an official answer.

Thank you again for your support.
Chloe-V 13,460 Reputation points Microsoft External Staff Moderator

2026-09-28T23:30:11+00:00

Hi @Vinh Ngo

Thank you for the update. I’m glad to hear that you were able to find a workaround that resolves the issue for now. I also appreciate you sharing your findings with us.