Exchange on-prem 2013 - 2016 users not able to send or receive messages from Gmail clients only.

Question

Hi, I am wondering if anyone else has experienced this issue, I currently have an Exchange Hybrid environment on 2013 Exchange server and one 2016 Server, some users have been migrated to MS 365 but most of our users are still on premesis. The issues I am having is this: on-prem mailboxes cannot send or recieve messages to any Gmail address or Google hosted domain, MS365 users however can send to Gmail but cannot receive, this just started Wednesday 6/14, all other domains messages are received and can send no problem at all. I am on of the Migrated users to MS365 and I have tested by sending a message to my personal Gmail account, I do receive it but when I reply back to my company email (outlook 365) I don;t receive anything, however, after about 2 hours I get a bounce message in my personal Gmail account with the following message: ("The recipient server did not accept our request to connect to smtp.mydomain.com and mail.mydomain.com") it supplies a support link but doesn't really tell me anything. This has just happened and it is only Gmail/Google related, anyone with any info or advise is appreciated. I can never get support from Microsoft, they are just a terrible waste of money, we have a support contract but never get any humans so I stopped even trying. Please Help.....

Answer 1

Hi @Fenton，Mark ,

Since we have the mail flow issue only with Gmail, on the one hand we could add the DNS records such as SPF,DKIM, DMARC and so on.

On the other hand, this may be caused by Gmail Inbound configuration. Perform reverse DNS to check the PTR record: https://testconnectivity.microsoft.com/tests/exchange

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Answer 2

I was able to resolve this issue by removing Symantec endpoint protection from my exchange server, seems for some reason this was blocking only Gmail messages but all others flowed freely, once removed Gmails where able to flow freely also.

Thanks for all the responses.