Slow IMAP operation

[alglyzin]

Letter Request Operation:

...
2023-08-20T21:06:01.330094Z TRACE session{instance="imap" protocol=Imap remote.ip="127.0.0.1" remote.port=37870}: imap::core::client: event="read" data="A0002 SELECT INBOX\r\n" size=20
2023-08-20T21:06:01.331206Z TRACE session{instance="imap" protocol=Imap remote.ip="127.0.0.1" remote.port=37870}: imap::core::writer: event="write" data="* 2 EXISTS\r\n* FLAGS (\\Answered \\Flagged \\Deleted \\Seen \\Draft)\r\n* 0 RECENT\r\n* OK [PERMANENTFLAGS (\\Deleted \\Seen \\Answered \\Flagged \\Draft \\*)] All allowed\r\n* OK [UIDVALIDITY 1692405654] UIDs valid\r\n* OK [UIDNEXT 5] Next predicted UID\r\n* OK [MAILBOXID (eaaaaaa)] Unique Mailbox ID\r\nA0002 OK [READ-WRITE] SELECT completed\r\n" size=322
2023-08-20T21:06:01.331655Z TRACE session{instance="imap" protocol=Imap remote.ip="127.0.0.1" remote.port=37870}: imap::core::client: event="read" data="A0003 UID FETCH 3 (UID RFC822.SIZE FLAGS INTERNALDATE BODYSTRUCTURE BODY.PEEK[HEADER.FIELDS (DATE FROM TO SUBJECT CONTENT-TYPE CC REPLY-TO LIST-POST DISPOSITION-NOTIFICATION-TO X-PRIORITY CONTENT-TRANSFER-ENCODING BCC IN-REPLY-TO MAIL-FOLLOWUP-TO MAIL-REPLY-TO MESSAGE-ID REFERENCES RESENT-BCC RETURN-PATH SENDER X-DRAFT-INFO)])\r\n" size=330

What was the IMAP server doing for 6 seconds ?

2023-08-20T21:06:07.807837Z TRACE session{instance="imap" protocol=Imap remote.ip="127.0.0.1" remote.port=37870}: imap::core::writer: event="write" data="* 1 FETCH (UID 3 RFC822.SIZE 6046 FLAGS (\\Seen) INTERNALDATE \"20-Aug-2023 16:49:44 +0000\" BODYSTRUCTURE 
...

The configuration is standard. There is only one mailbox with 2 letters. I don't understand why it's slowing down?!

[mdecimus]

Can you describe your setup?

• Which database backend are you using?
• Which blob store are you using?
• Which Stalwart version are you using?

Also, how big are those messages? Do they have a large number of headers?

[alglyzin]

1. MySQL
2. S3
3. 0.3.5

The content of the messages is just a string: test

[mdecimus]

It looks like the delay occurs while accessing your S3 storage. Can you try using local storage? If there are no delays verify why is your S3 storage taking so long, might be a connection issue or something else.