Fri, 10 Apr 2026 01:39:30 +0000 https://bugs.horde.org/ticket/7789 too much IMAP traffic with IMP 4 I have IMP 3 and IMP 4 both running on the same server -- same hardware, same operating system, same apache, same php. With IMP 3, listing a mailbox takes less than 1 second. With IMP 4 it takes 5 seconds. So, I used tcpdump to trace the IMAP traffic, and found IMP 4 is doing far too much work. My test mailbox has about 1000 messages, IMP is configured to display 100 per page. With this setup, IMP 3 does 6 IMAP FETCHes, IMP 4 does 305 IMAP FETCHes. In addition, it looks like IMP 4 is fetching the same group of messages (106:125) over and over again. IMP 3 IMAP Trace: LOGIN ... CAPABILITY SELECT bulk LSUB "" * LIST "" INBOX FETCH 1:20 (UID ENVELOPE BODY PEEK[HEADER.FIELDS (Newsgroups Content-MD5 Content-Disposition Content-Language Content-Location Followup-To References)] INTERNALDATE RFC822 SIZE FLAGS) FETCH 21:1299 (UID INTERNALDATE RFC822 SIZE FLAGS) SEARCH UNSEEN FETCH 21:40 ... FETCH 41,42:61 FETCH 62,63:82 FETCH 83,84:103 LOGOUT IMP 4 IMAP Trace: LOGIN ... CAPABILITY STATUS bulk ((MESSAGES.RECENT.UNSEEN.UIDNEXT.UIDVALIDITY) EXAMINE bulk UID FETCH 1 UID UID FETCH 2 UID UID FETCH 3 UID ... UID FETCH 98 UID UID FETCH 99 UID UID FETCH 100 UID FETCH.1,2:21.(ENVELOPE.BODY.PEEK[HEADER.FIELDS.(Newsgroups.Content-MD5.Content-Disposition.Content-Language.Content-Location.Followup-To.References)].INTERNALDATE.RFC822.SIZE.FLAGS) FETCH 22,23:42 ... FETCH 43,44:63 ... FETCH 64,65:84 ... FETCH 85,86:105 ... GETQUOTAROOT bulk FETCH 1,106:125 (BODYSTRUCTURE.FLAGS) FETCH 1 BODY PEEK[HEADER] FETCH 2,106:125 (BODYSTRUCTURE.FLAGS) FETCH 2 BODY PEEK[HEADER] FETCH 3,106:125 (BODYSTRUCTURE.FLAGS) FETCH 3 BODY PEEK[HEADER] ... FETCH 99,106:125 (BODYSTRUCTURE.FLAGS) FETCH 99 BODY PEEK[HEADER] FETCH 100,106:125 (BODYSTRUCTURE.FLAGS) FETCH 100 BODY PEEK[HEADER] LOGOUT Thu, 18 Dec 2008 19:01:41 +0000 https://bugs.horde.org/ticket/7789#t51338 #1 - You can't compare IMP 3 and IMP 4 - IMP 4 is doing vastly more stuff than IMP 3, so there's going to be some level of extra IMP traffic. #2 - You are almost certainly not using caching. If you care about performance at all, you need to be caching IMAP data. #3 - As for the terribleness of the IMAP commands actually sent to the server - this has nothing to do with the Horde project. We use the c-client IMAP library - it is what is sending the commands to the server. I won't even begin to describe the inefficiencies of the IMAP commands it sends. This is why an entirely new IMAP library has been written for IMP 5. Thu, 18 Dec 2008 19:10:10 +0000 https://bugs.horde.org/ticket/7789#t51340