Iphone Exchange Accounts does not work

Good day,
Have the following problem. Can set up the Exchange profile with my Iphone. Receive only a few emails. After some time the error message comes …

Do you use sogo or webtop?
Here are instructions for webtop and ios:


Dear Mr. Neuberger …

Thanks for the support.
I use webtop. I have followed this, unfortunately, the iphone calls only about 200 emails until it then receives this error.

Webtop developers recommend using Activesync (Exchange) only to synchronize contacts and calendars. For mail it is better to use imaps and smtp

Have also tried with Sogo … unfortunately synonymous the same problem.

Do you use let’s encrypt certificate or self-signed?

Dear Mr. Ballarini
I use the self-signed certificate

Could you try to set up a let’s encrypt certificate and see if something changes?

I have set up the server again. Unfortunately without success.
With a small inbox folder works !! Why

I think you can solve by configuring account in IMAP and then use ActiveSync only for calendars and contacts, like @saitobenkei suggestion.

P.s. anyway try to require a let’s encrypt certificate.