Outlook Randomly stops getting email

Question

outlook randomly stops receiving emails and i have to log out/in or reboot pc to start getting emails again.

I have a weird issue, recently after we migrated a company to O365.

--Running Windows 10

--All machines are joined to azure ad (o365 environment)

--Sentinelone is installed

--network firewall is meraki

--desktop/documents are synced with onedrive

--our bandwidth is 900 down and 35 up

--20 people in the office

--PC are new Dells

--Mac users in the office have none of these issues

--OWA or my mobile phone works fine and i never stop getting emails

Issues we are facing is outlook randomly stops receiving emails, to fix this we have to log out and log back in or reboot. if you close and reopen outlook it wont work.

We tried the following:

--reimaging a machine

--getting local ISP to replace their modems and confirm our bandwidth is good

--eliminating wireless

---disabling sentinelone

anyone run into this and have a solution?

Answer 1

Hi @DN ,

According to my research, I have found a similar thread: Outlook not receiving emails unless Outlook is closed and reopened

The answer under the post mentions that in cached mode, when ost files reach the limit, this will cause slow sending and receiving emails, so it is recommended that you reduce the slider of cached mode to 3 months to see if the problem can be solved:

1. Click File > Account Settings > Account Settings.
2. Click your account, and then click Change.
3. Under Offline Settings, move the slider to the 3 months.