Mail Export mailbox… and Copy messages functions do not work when IMAP account is offline

Originator:pguyot
Number:rdar://34076819 Date Originated:8/25/2017
Status:Open Resolved:
Product:Mail Product Version:10.3 (3273)
Classification:Data loss Reproducible:I did not try
 
Summary:
When an IMAP account is offline, Mail.app "Export Mailbox…" function produces an empty .mbox file.
Likewise, copying messages to a mailbox on another IMAP account does not work (some but not all messages are eventually copied).

Messages that could not be copied seems to have separate attachments (in Library/Mail/V4/.../Attachments/.../ subdirectory).

As a consequence, in case of an IMAP server crash, mail could not be easily recovered.

Steps to Reproduce:
Take a large IMAP account offline. Try to export a mailbox of this account by control-clicking on it and choosing "Export Mailbox…"

Expected Results:
Mail.app should generate a full .mbox file that could be used with another mail software (typically be imported in a new IMAP server).

Observed Results:
The .mbox file within the bundle is eventually empty.

Version:
Mail Version 10.3 (3273) 
OS X Version 10.12.6 (16G29)

Notes:
It sounds like Mail.app does not include the required feature of reinflating RFC822 messages by re-encoding attachments that were extracted for Spotlight/QuickView features. Original Content-Transfer-Encoding header and added X-Apple-Content-Length header can be used to build a compatible message but they are actually not sufficient to re-inflate the message exactly like it was initially received.

Comments


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