Hello SmarterTools,
A customer reported an issue with IMAP on SmarterMail, discovered while he tried to use the imap-backup utility.
As per the developper of the tool, SmarterMail IMAP implementation is answering wrongly when using the EXAMINE function.
When using EXAMINE (or SELECT) on an non-existing folder, it should return "NO", and not "BAD" which would mean there is an error calling the command.
as per the RFC:
I went ahead and tested the command manually on SmarterMail, trying to EXAMINE or SELECT an non-existing mailbox:
a1 LOGIN user pass
* CAPABILITY IMAP4rev1 AUTH=CRAM-MD5 AUTH=NTLM AUTH=PLAIN SASL-IR UTF8=ACCEPT UIDPLUS QUOTA MOVE XLIST CHILDREN ENABLE CONDSTORE X-SM-TAGS IDLE
a1 OK LOGIN completed
a2 EXAMINE toto
a2 BAD EXAMINE mailbox does not exist
a3 SELECT toto
a3 BAD SELECT mailbox does not exist
I tried the same on other mail system (base on dovecot for IMAP):
a1 LOGIN user pass
* CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SNIPPET=FUZZY PREVIEW=FUZZY PREVIEW STATUS=SIZE SAVEDATE LITERAL+ NOTIFY METADATA SPECIAL-USE COMPRESS=DEFLATE QUOTA ACL RIGHTS=texk
a1 OK Logged in
a2 EXAMINE toto
a2 NO Mailbox doesn't exist: toto (0.001 + 0.000 secs).
a3 SELECT toto
a3 NO Mailbox doesn't exist: toto (0.001 + 0.000 secs).
It's correctly answer, according to the RFC.
It then seems that the utility developer is right. SmarterMail is not answering correctly to the command when a folder doesn't exists.
The imap-backup tool use this to check if a folder needs to be created, while restoring a backup. As it returns BAD instead of NO it will abort the process because it is considered as if the command failed.
It maybe can also have some kind of side effects on mail clients using IMAP that is excepting a NO answer when using SELECT and EXAMIN functions on a non-existing folder.
Can we have a fix for this kinda trivial change the next build please ?
Thanks a lot.
Kind regards.