IMAP: Moving data slow with emclient 9!

Moving data to the folder the background task is slow:
It moves an email every 2 seconds:

IMAPD 18676 46 2022-02-28 02:04:16.854 SENT: * SEARCH 27973
IMAPD 18676 46 2022-02-28 02:04:16.858 SENT: A73 OK UID completed
IMAPD 18676 46 2022-02-28 02:04:16.860 RECEIVED: A74 UID SEARCH HEADER Message-Id
IMAPD 18676 46 2022-02-28 02:04:18.674 SENT: * SEARCH 27972
IMAPD 18676 46 2022-02-28 02:04:18.678 SENT: A74 OK UID completed
IMAPD 26916 46 2022-02-28 02:04:18.680 RECEIVED: A75 UID SEARCH HEADER Message-Id d466eb364d112c6d52cd1827bd81e8c6@swift.generated
IMAPD 26916 46 2022-02-28 02:04:20.495 SENT: * SEARCH 27971
IMAPD 26916 46 2022-02-28 02:04:20.499 SENT: A75 OK UID completed
IMAPD 7032 46 2022-02-28 02:04:20.501 RECEIVED: A76 UID SEARCH HEADER Message-Id eme8cec002-e0f9-4a3d-9618-7674bf4348cf@kseniachri

Both IMAP server and emclient are on NVMe disk connected localhost.

Any ideas ?

If you are saying you are eg: pulling mail via a local IMAP LAN mail server connected to a remote IMAP mail box, you may have a problem with your local lan mail server configuration either serving the mail to eM Client or remotely receiving the mail from your IMAP mail box to you via the LAN.

If you are doing that, what happens if you directly receive mail from your IMAP remote mail box “as normal” and “bypass” your local lan mail server ?

Also what ver of eM Client are you running and do you have Windows or Mac and what OS ver ?

Windows hmailserver and emclient is on localhost ( on the same machine.

Ok I haven’t ever seen Hmail server before and it’s not one of the supported eM Client mail servers.

eM Client Compatibility

eM Client is enterprise-grade software compatible with all major platforms. We fully support these systems.

So suggest to contact Hmail server support for assistance as to this issue.

There maybe someone otherwise on this free forum who has run that mail server before that can help you. Sry I cannot help with that.

If you are a current paid eM Client Pro or Enterprise customer you can contact support via the Pro / Enterprise page and lodge a VIP ticket where they may be able to assist you further.

Hi Michael,
it seems that your IMAP server does not index some header information, such as message-id which slows down the operation.
It could be resolved with a special parameter --imap-avoid-search-by-messageid so eM Client does not even try to use the message-id to find your messages on the server and uses other details instead.
Put this parameter in Menu>Accounts section in the Diagnostics tab of the affected account.

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Dear Cyberzork,
hMailServer is widely used globally!
I use it on several companies i support along with emClient 8 Pro without problems so far!
Also I use roundcube with hMailServer without any problems too!

Thank you

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Dear Olivia,
Thank you! It worked!
Maybe you could detect that on startup and disable it automatically if the IMAP server doesn’t support it ?

Thank you

UPDATE: The --imap-avoid-search-by-messageid is actually solved the problem with speed problems but it creates empty dupes when i move messages to “Trash”. Removed the parameter it worked as expected but with the delays …

Thank you for the feedback. The parameter is not fool-proof in all cases and that is exactly why we do not apply it by default.
I have discussed the issue with our IMAP expert and he recommends trying this parameter instead and see if that helps:

Dear Olivia,
Unfortunally --imap-search-for-messageid-with-date also causes the same type of problem as --imap-avoid-search-by-messageid. Maybe emClient 9 isn’t tested using those IMAP parameters ?

Thank you

Hi Michael,
the issue is more on the side of the fact that no matter how many different testing accounts and servers we have we will never be able to replicate all possible combinations of IMAP behavior.
I think that to resolve the issue we might need more data and maybe even a test account on your server if possible?
If you are willing to troubleshoot further this way, please reach out to me directly at

Yes i understand! I’ll try to setup you a hMailServer VM and emClient!

Thank you

I had the problem that mails did not appear when using IMAP. All clients work for the mailserver, but emClient did not in combination with hMailserver.
Today I found out that disabeling the NOD32 IMAP-scanner (Settings → E-mailclient → E-mail-protocols → IMAP → disable) solves the problem for me. If any of you experience problems with the combination hMailserver and emClient, see if disabeling your virusscanner solves the problem. It might have impact?