Hi,
I’m unable to configure mail server on my ubuntu box.

First I tried iRedmail, which I’m familiar with and I had no problem setting up in the past but this time I was unable to send the email (I was able to receive the mail just fine).

Now I’m using “Mail in a box” and still not able to send the mail.

I followed this tutorial to install “Mail in a box”.

I followed every step but it’s saying 25 port is blocked by the network but I checked on my server, the port is open

Screenshots
https://ibb.co/dh4wfv
https://ibb.co/kj807a

Note- The only thing I didn’t follow from the tutorial is that, my droplet name is not same as my hostname. (Droplet name- inprinters.co.uk, Hostname- box.inprinters.co.uk)