Problems with Inbound Email

Friends, after have some port issues (looks like m RV345P stopped responding to forwarded ports), I'm faced with the fact that email from OUTSIDE-THE-NETWORK sources are not making to accounts within my network and cPanel installation. Emails sent WITHIN my network ARE making it OK to other users. Additionally, I noticed that my email client (thunderbird) is no longer probing for email settings when an email account is setup in the client? Any suggestions is appreciated.