SMTP email fails with Amazon SES — malformed MIME boundary (v0.8.9) #372

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1. thegingerninja commented on Oct 23, 2026

   

   thegingerninja

   on Oct 23, 2026

   Author

   More actions

   diff --git a/internal/smtp/notification_sender.go b/internal/smtp/notification_sender.go
   --- a/internal/smtp/notification_sender.go
   +++ b/internal/smtp/notification_sender.go
   @@ -1,2 +1,7 @@
   -	headers := fmt.Sprintf("From: %s\r\nTo: %s\r\nSubject: %s\r\nMIME-Version: 1.0\r\nContent-Type: multipart/alternative; boundary=%s\r\n",
   -		from, to, encodeHeaderWord(opts.Subject), boundary)
   +	contentType := mime.FormatMediaType(
   +		"multipart/alternative",
   +		map[string]string{"boundary": boundary},
   +	)
   +
   +	headers := fmt.Sprintf("From: %s\r\nTo: %s\r\nSubject: %s\r\nMIME-Version: 1.0\r\nContent-Type: %s\r\n",
   +		from, to, encodeHeaderWord(opts.Subject), contentType)
   
2. stefan-ernst

   added a commit that references this issue on Oct 23, 2026

   fix: build outbound MIME with mime/multipart (WI-1865)

   ...

   86fd7b2