Correctly set up DNS for sending email via Wordpress and SMTP

Question

I've recently moved my website to a new server.

I've changed the DNS record to use the new server for the website but, I'm still using the old one as a mail server. So, basically, the DNS is set up to the new server for the normal web traffic and to the old one for email (MX on the DNS).

Now, I have a contact form on Wordpress that should be able to use one of my email address.

I've set up the email address to work as SMTP on my server but it seems not working.

I've not added records for that on the DNS; I've just the record that directs the mail traffic to the old server. Do I need and, in case, which records should I've to add?

Answer 1

Providing your old server is properly configured then the problem shouldn't be with the DNS records. Moving your website to the new server should have only required changing the A records for example.com and www.example.com, not whatever subdomain is pointed to your mail server.

Double check that your mail server is configured for something like smtp.example.com or mail.example.com and that the IP address is for the old server. Then make sure in the mail server settings, it knows to accept mail on that address.

If the WordPress site was able to send mail via SMTP prior to the move, you should ensure that your mail server has the new server whitelisted for sending mail and that the site is using the correct authentication methods.

Answer 2

So the problem was a misconfiguration of Email Routing on cPanel.

The solution has been, selecting my subdomain email on Email Routing in cPanel and instead Automatically Detect Configuration I need to choose Local Mail Exchanger

Now the mails via the SMTP and subdomain are correctly received from the mail server.

The DNS servers were configured in the right way tho.