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TLS 1.0 and 1.1 not supported Office365

Posted: Wed Jan 05, 2022 11:53 am
by Mazurizi
Script URL: Internally hosted
Version of script: 3.2.4
Hosting company: Internally hosted
URL of phpinfo.php:
URL of session_test.php:
What terms did you try when SEARCHING for a solution: TLS

Write your message below:

We are getting the intermittent errors and emails not sending. When trying the Test SMTP connection button it is popping up saying: Error: 421 4.7.66 TLS 1.0 and 1.1 are not supported. Please upgrade/update your client to support TLS 1.2. Visit https://aka.ms/smtp_auth_tls. [LO4P123CA0244.GBRP123.PROD.OUTLOOK.COM]

I've had a look at the page that it links to but I'm unsure whether updating your 'client' would be hesk, or the server that it is hosted on.

SMTP Settings are:
SMTP Host: smtp.office365.com
SMTP Port: 587
SMTP Timeout: 20
SSL: Off
TLS: On

If you are able to offer any guidance it would be greatly appreciated as always.

Thanks in advance.

Re: TLS 1.0 and 1.1 not supported Office365

Posted: Wed Jan 05, 2022 3:51 pm
by Klemen
The TLS used depends on the server setup, it's not something Hesk sets. We have many clients using Hesk successfully with O365.

What I would do is make sure your server software is updated, for example, Apache/OpenSSL/PHP (or whatever other server software you use).

Re: TLS 1.0 and 1.1 not supported Office365

Posted: Thu Jan 06, 2022 8:36 am
by flaco
Strange,

I'm also running O365 with Hesk.
Thew same exact settings and don't have these issues.
What you can try is ask your hoster, perhaps there are some setting in place witch blocks this traffic.