I have three Wordpress sites on this droplet. The first two send emails fine. The third one, which I have set up recently, will not send emails - not from contact us forms, nor from trying to change the admin email. The forms etc appear to work fine but no email ever shows up.

I am using Migadu. Sending emails manually from this domain is fine. So I don’t think it’s the DNS.

Nothing shows up in /var/log/mail.log. In fact this file has not been edited since 2018. Same for mail.log.1

I tried using WP Mail SMTP plugin and pointing it at Migadu SMTP. This doesn’t work, it says “There was a problem while sending the test email” when testing.

I never had this problem when I set up the second Virtual Host site. What could be causing this?

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2 answers

Hi @umpire,

You’ve been on the right track, the best way to make sure your e-mails will be received is using a plugin for SMTP, like in your case WP MAIL SMTP.

Yes, you mentioned you received the error “There was a problem while sending the test email” however this I believe is because of the port you’ve used to be set as closed. So, I believe you’ve either used port 465 or 587 to send the e-mails, correct? Either of these should be allowed for outgoing connections in order for you to be able to send out e-mails using Migadu.

You can allow either port with the following two commands

sudo iptables -A OUTPUT -p tcp --dport 465 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
sudo iptables -A INPUT -p tcp --sport 465 -m conntrack --ctstate ESTABLISHED -j ACCEPT

Or for port 587

sudo iptables -A OUTPUT -p tcp --dport 587 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
sudo iptables -A INPUT -p tcp --sport 587 -m conntrack --ctstate ESTABLISHED -j ACCEPT


  • Hi @KFSys

    You’re 100% right, it’s the port. I used a plugin (WP Mail SMTP) to fix it (specifying Migadu SMTP with the 587 port).

    Would your method help me to do this without the need for a plugin?

    And do you have any idea why my other sites on this droplet are working fine? Same mail setup with Migadu/Wordpress but no need for the plugin.


    • I would recommend using the Plugin otherwise your website will use the normal PHP mail function which is considered by many as a spam tool rather than a legitimate one.

      As for your second question, I can’t really tell you here, it might need further troubleshooting to understand why the other two websites are sending out mails.

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