It will help if you explain errors you are encountering and/or that your accountant is encountering.

Hi David, I sent an email to my accountant requesting some information. When I didn't hear back from him, I sent a second request. I still didn't hear back from him, so I called him. He said both he, and one of his staff had replied to my email. I never received their replies. I did the recent upgrade to Thunderbird, and tried again, with no luck. They receive my emails, but I do not receive the ones they send. I have always been able to receive their emails for many years previously. I hope this helps.

Can you read their messages from your online account? Is it possible they're going to a spam filter?

I am not sure how to view from an online account - I'm sorry. Why would it have a spam filter now if it didn't before?

For online accounts, here is an example: If your email id is gmail, you can read mail online at the gmail dot com website. If an outlook account, you can read online at outlook dot com. I don't know your email id, but you can contact your email provider on how to access the account online.

Hello mcgamble

do you receive mails from other persons ? Is your accountant getting an error notification that mails to you are not distributed ?

Hello gp, I do receive other emails constantly. I don't think my account gets an undelivered message - he had assumed I had gotten his replies until I called him. But, I will check with him. Thank you.

Well, ask him if the notification could have gotten in a junk folder or neglected in another way (sometimes people don't understand these messages that are a bit technical and just delete them)