emails are bouncing back when sending to yahoo

I am getting the exact message as "mpur" posted. From what I am reading am I to assume this error is really a YAHOO account issue. They must have changed some security feature on their accounts and they are blocking anyone that doesnt have a YAHOO account. I am a travel agent and all of my clients emails are bouncing back as undeliverable. It is not in their spam/junk folder. Please find a solution to this quickly. thanks!

No way would they block outside email users. It wood make yahoo mail useless. And the error message would be different. What it shows now is that when the Microsoft SMTP server tries to connect to the Yahoo server there is a socket connection error, the kind of thing you'd get with a firewall blocking you, and it's not that.

I'm in the middle of business tech support work Microsoft on this and it's my impression they have no idea what it is. They have me fixing things that can't possibly be the problem. I pointed tech support to this thread to show site that I'm not the only one.

Apparently this is nothing new with Outlook vs Yahoo accounts. You can search and see that as far back as 2013 this has been an ongoing problem between them. I am not sure who is at fault here but it needs to be fixed. I pay way too much money for Office 365 and use the Outlook desktop version to deal with ongoing issues.

I am having the same issue.

We are using a business account.

Four separate bounce backs:

X 2 Yahoo accounts.

X 2 AOL Accounts.

Any advise would be appreciated.

Interesting. I've had this Office 365 account for a long time, at least 10 years, and I regularly email with yahoo.com accounts. I don't recall this kind of error being persistent before.