Zoho.com mail (exchange) gets stuck in outbox [released]

These are the settings that I use for Zoho https://together.jolla.com/question/38909/heres-zohocom-exchange-settings-that-work/

I am experiencing the same problem with an Exchange account of german webhoster Strato (strato.de). I can receive mails without problems but if I try to send a mail it gets stuck in outbox. When I click on "send message" the email application is trying to sync with the exchange server and after a while it indicates "synchronisierung fehlgeschlagen" (synchronisation failed). I can see the mail in outbox then.

But in contrast to Wizah I didn't have this problem ever since I'm using Jolla. Sending mails didn't work with SW versions before update 3, but after that and also with current version (1.0.5.16) sending emails worked for a while. Maybe a week ago it stopped working, although I didn't change anything in phone/mail settings. Is there some logfile or something like that where I could see the reason for the failure?

Logs would be helpful, enable logging in the following file:

/home/nemo/.config/Nokia/activesync.conf

Enable file log and add a path for the log, like for example:

   [FileLog]
   Enabled=1
   Path=/home/nemo/Documents/as.log

Reboot the device and reproduce the problem, examine the file to see if you want to remove some data, your email address, calendar entries names and folder names can be presented there, send me the logs to mail-logs at jolla dot com. After that turn file log off again by setting "enabled" to 0.Thanks a lot!