Unable to send e-mails from Office 365

[teegeepee65]

mail undeliverable from all 3 of my accounts. error message 

550 5.7.1  Reject for policy reason.  I have not changed any settings. Had the same addresses for years. Suddenly stopped working today

[Ady-TalkTalk]

As your mailbox hasn't been limited to webmail only please try removing the account from Outlook, restart Outlook, add the account back and then restart Outlook again. This often resolves Outlook issues.

Ady

[teegeepee65]

I can send to other email addresses only from Webmail. If I send an email back to myself it sends it to the spam folder. Emails work fine from my phone.

[Ady-TalkTalk]

Do I understand you correctly? Are you able to send and receive from TalkTalk Webmail, but not from email clients?

[teegeepee65]

reset passowrd but made no difference. Can send e-mails from my phone but not from desktop or laptop. sending e-mails from gmail to talktalk sends them to the spam folder. hope this helps.

[Ady-TalkTalk]

Hi teegeepee65, at present the tool needed to check if this is a hard block that needs lifting at TalkTalk's end is down. In the meantime you should reset the password for one that's never been used before. This may restore your ability to send mail. If it doesn't please post back to let us know. 

Ady

[Flaneuse]

I'm getting the same with Outlook. Can receive OK, it seems. Can send to gmail.com but rejected from sky.com and .plus.com addresses as well as an organisation's own *****.org.uk address.