Outlook Intermittently disconnecting \ trying to connect to server

Backup the mailbox to pst
then remove the mailbox
create new mailbox
recover from pst to ost

Looking at this it look to issue with specific machine,

1- Did you try to configure other profile on the same machine and check the behavior?
2- Disable the AV and see
3- compare the difference between the working and non working machine
4- If nothing works unfortunate you will have to install the fresh OS on the machine

Hello

I recommend you validate the event viewer to see what other errors we found and share them to help you

regards..

Hi,

Apologies for the slow reply, I haven't been in over the bank holiday.

@Pradnip Singh - 1. No, I didn't test a different mailbox but I'll get back on the user's machine today to test.
2. I'll also try disabling the AV when I get back on the user's machine.

@Rafa - I'll have a look at the event viewer and let you know my findings.

@Hani - I am backing up the mailbox now so will try this once complete.

In account, I will be attentive.

Additionally Does this issue only occur to one specific computer?

Have you installed some anti-virus software on this PC? As far as I know, these programs will intergrate with Outlook client. To eliminate it, please temporarily close these antivirus programs and then see if issue continues.

Do you have cached Exchange mode enabled? We can also switch to online mode to test the results.

Regards...

Hi,

I am unable to create a new profile in Outlook - I tried three different accounts on the same domain and one on a separate domain and all say 'An encrypted connection to your mail server is not available'

This is with the AV disabled

Cached exchange mode was enabled and Outlook fails to open in online mode.

Any further suggestions welcomed.

Try accessing the OWA if okay try to create a  profile on different machine
if still same capture the fiddler and see where the request is getting terminated

The profile sets up no problem and stays connected on another machine.

I'm not sure what I'm looking for on the fiddler?
I can see it often says,
eweb.domain - no cache, must revalidate
domain:port# - no cache, must revalidate
autodiscover.domain:port# - no cache, must revalidate
autodiscover/autodiscover.xml - no cache
autodiscover-s.outlook.com - expires: today's date and time.