Hello. After setting up default incoming email and getting it working, I would get a To Do message from Administrator after two or three days saying “Invalid Mail Server. Please rectify and try again.” I would go to Email Account and check Enable Incoming again. Is this normal? I’m using a free account from gmail and pulling from imap.gmail.com.
Thank you for your time! 
@airzoink where do you host your ERP? it might be a DNS issue in the server or resolver issue, i am using incoming email for 4 aliases but not issues.
I’m hosting my own ERP server locally. Any suggestions on how to troubleshoot this issue?
@airzoink try to set another mail service for testing, I think it’s the Api calling on your server the authorize to gmail expires and don’t update the session until you reset the authentications…
I re-setup my incoming and outgoing email and everything seems to be working fine now. I’ll continue to observe its behavior. Thanks for the advise.
After one week of observation, the issue returned which happens once a day.
I would just like to clarify if i am setting it up correctly. I’m using the same email address for both incoming and outgoing. Under Setup–>Email Account i have Sales Reply (incoming) and Sales (outgoing) entries. Is this the right setup? Any suggestions?
Thanks! 
@airzoink why are you using two different entries for the same email? am not sure if gmail have a limit on account logins or not, you have to try to set it up using another email provider.
I just ended up with that setup as I was trying it out. I changed it to one entry (both incoming and outgoing) for one email. So far so good.