Archive Mailbox certain messages possibly failing on special characters

While archiving my mailboxes today, I noticed a significant number of ‘Couldn’t write message file. Can’t continue import of message.’ errors in the Log.

Looking for possible causes in the log file, it seems that special characters are tripping up the process, either in the subject or the sender name. All failed imports included characters like ', (, ), *, or emoticons.

Has anyone else seen this behavior and what can I do to confirm this hunch?



what can I do to confirm this hunch?

Or deny it? :wink:

  • What language are the emails in?
  • What email client are you pulling from?

The emails are in dutch, english, some french, the email client is Apple Mail v16.0

When I retried the import, I also noticed messages failing without special characters in the subject and sender fields, so it’s getting a bit confusing now. The error message still remains ‘Couldn’t write message file. Can’t continue import of message.’. All the failed messages in the retry also appear to be on the same date, exactly one month ago.

When I check if the other emails have made it into the archive, I can’t find them. I do see that the substructure of my inbox is replicated in the mail archive, and that said substructure was created on the same date that is failing. I deleted the substructure since it was empty and retried again, getting the same 15 failures again, without that substructure being created.
Looking at the substructure in general, the Archive does not reflect that actual substructure in Mail.

Full disk access has been given to DEVONthink.

I would do a Mailbox > Rebuild in Apple Mail.

Any chance that you could export any of these emails, zip them and send the archive to cgrunenberg - at - This would be useful to reproduce this. Alternatively you could redirect (not forward!) the emails to this address.

On another hunch, I moved to a different laptop and tried the import again, this time without any failures.

What I will do is first follow Bluefrog’s recommendation of rebuilding the mailbox, then looking at any obvious differences in patch-levels, plugin age etc. and retry.

When this has been completed, I’ll report back.

Much appreciated!