SMTP Permanent Error 530 - Must Use TLS

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1

**Domino/Notes Version: 9.0.1 FP10
**Add-on Product (if appropriate, e.g. Verse / Traveler / Nomad / Domino REST API): NA
**Its Version: NA
**Operating System: Windows Servre 2008
**Client (Notes, Nomad Web, Nomad Mobile, Android/iOS, browser version): 14.0 FP4

We are receiving the following error when send to s particular address and not sure if it’s our end or their end?

Error transferring to juneeshire.in.tmes-anz.trendmicro.com; SMTP Protocol Returned a Permanent Error 530 5.7.0 Customerserviceteam@XXXXX.nsw.gov.au: Recipient address rejected: Must use TLS

Please advise if there is any action we should be taking.

2

Hi.
As a matter of fact, yes.
In simple words, you’re currently sending emails out in plain text.
You need to enable TLS for Outgoing traffic.
You may refer to the following:

Hope this helps.

Best,
Elvis

3

Thanks, Elvis, for your reply.

Would you mind resending the link to the documentation as the current one does not work correctly.

4

Oh. Apologies. Im not sure what may have happened.
Sure thing. Here it is:

Best,
Elvis

5

Hi,
yes you need to enable SSL/TLS as Elvis said.
Check what is the version of SSL/TLS supported by Domino 9.0.1FP10.
It could be that it is old. If the server does not have SSL certificates installed you might need to get some. New Domino versions can get them for free and automatically from Let’s Encrypt.
Consider routing outbound SMTP email to a small Linux box that you can keep updated easily and with new and free certificates. It could also be an smtp server available from your internet provider.
If you do not want all of your email going to another server, you might consider routing only email for that domain to that alternative smtp relay.
Mike

6

Hi, @ppeckman .

You may also check the troubleshooting steps mentioned in this knowledge article:

Configuring Domino for secure SMTP sessions using STARTTLS

Regards,
Christian Sinfuego