450368 - Gmail IMAP creates single copy of mail only, when multiple copies of same mail in local mail folder are copied to a Gmail IMAP folder(looks to be mail loss for user), and if different tag is set on mails, tags are merged on the single copy

Status: RESOLVED INVALID

(MailNews Core :: Networking: IMAP, defect)

Description

[WADA:World Anti-bad-Duping Agency]

Attachment: IMAP log for copy to Gmail IMAP folder from local mail folder

Gmail IMAP creates single copy of mail only when multiple copies of same mail in local mail folder are copied to a Gmail IMAP folder(looks to be mail loss for user), and if different tag is set on mails, tags are merged on the single copy.

Tested with Tb trunk 2008/8/09 build.
[Test procedure]
(0) Gmail IMAP folder of Text/X9 is not opened. Mail count=0
(1) At a local mail folder:
    Copy a mail to other local mail folder(say Folder-L) 5 times.
(2) At Folder-L: Add tag to mails
    mail-1:$label1,mail-2:$label2, mail-3:$label3,mail-4:$label4,mail-5:$label5
(3) At Folder-L: Copy the 5 mails to Gmail IMAP folder(Test/X9)
(4) Mail count of Test/X9: 5
(5) Click Test/X9(open Text/X9)
    Mail count becones 1. One mail only in the folder.
    All of $label1 to $label 5 is set on the only one mail.

I think above is simply a result of special design/spec of Gmail/Gmail IMAP.
  - Single instance of mail data
  - Mail filtering(duplicated mail is not saved) 

If COPY operation to Gmail IMAP for multiple local mail copies is executed on different day, it looks to be "mail loss" for user. 
This is another "silent delete of mail by Gmail IMAP" case.

Comment 1

[WADA:World Anti-bad-Duping Agency]

(Note-1)
Above is applicable to MOVE too.
(Note-2)
Above occurs when copy/move from Gmail IMAP folder to Gmail IMAP folder too.
However, I guess that duplication check of mail data by Gmail's filter is not executed in this case, because Gmail IMAP already knows about "single instance of mail data" for the mail.

Comment 2

[WADA:World Anti-bad-Duping Agency]

Note:
This bug will be closed as INVALID soon, because this bug's phenomenon is due to special Gmail/Gmail IMAP design/spec(never be Tb's fault).
This bug's purpose is to help analysis of funny phenomena with Gmail IMAP, and to help Bug 450227.

Comment 3

[WADA:World Anti-bad-Duping Agency]

Note:
"same mail" in bug summary == same mail for Gmail != abosolutely same mail data
Example:
     mail data passed to SMTP      : no   BCC:, no Received:, ...)  
  == sent mail copy saved in Sent  : with BCC:, no Received:, ...)
  == arrived mail to Inbox         : no   BCC:, with Received:, ...)

Comment 4

[WADA:World Anti-bad-Duping Agency]

(In addition to comment #3)

For Gmail,
     (A) mail data passed to SMTP     : no   BCC:, no   Received:, ...  
  == (B) sent mail copy saved in Sent : with BCC:, no   Received:, ...
  == (C) arrived mail to Gmail        : no   BCC:, with Received:, ...
It produces user's confusions.

(Confusion-1)
If Gmail's SMTP is used, (A) is written by Gmail's SMTP+Gmail first (in [Gmail]/All Mail, [Gmail]/Sent Mail).
So, (B) by mail client including Tb is not kept by Gmail. Some peoples call it "loss of BCC: header" and consider it Tb's bug.
If myself is included in To:/CC:/BCC: of the mail, arrived mail of (C) is not kept by Gmail.

(Confusion-2)
If Gmail's SMTP is not used, (B) is wrtten by mail client(Tb) first (in [Gmail]/All Mail, [Gmail]/Sent Mail or something). So, if myself is included in To:/CC:/BCC: of the mail, arrived mail of (C) is not kept by Gmail.

(Confusion-3)
If Gmail's Web Interace is used for mail sending, (B) is wrtten by Gmail first (in [Gmail]/All Mail, [Gmail]/Sent Mail). So, if myself is included in To:/CC:/BCC: of the mail, arrived mail of (C) is not kept by Gmail, or Gmail won't add Gmail Label of "Inbox" to the mail.

Comment 5

[David Lechner (:dlech)]

Bugday cleanup. Closing per whiteboard.