Attached files take forever to download from Kerio (imap) account

I have a Kerio account (IMAP) and attached files in messages, even if they are very small, takes forever to download (compared to Thunderbird or Outlook).
By the time eM Client has finished downloading the file, I can log in to my webmail, download the file from there and read it, and eM Client is still not done.

The problem is for any message with attached file. It is a little bit better with Gmail account.


Kerio provides email accounts? Or you mean that you are using gmail and you let your messages trough kerio which scans them for malware and viruses?

If this is happening only with messages with attachment can you please check if kerio is scanning them when they are being downloaded?



may email is a kerio server based email ( provided by GetSyncd (
The download with any other email client (outlook or thunderbird or mac mail) or through webmail is fast.

With em Client it may take 30 seconds for a 100kb document. I have some large attachment (9 MB) that never finished downloading with eM Client

then in this case I will need your IMAP logs, go to tools - settings - advanced, check IMAP under your account, apply and restart eM Client.

Simulate steps that leads to your issue and after that send logs… to together with this topic’s URL in subject.

then you can turn logging off.