Fix and update mailcatcher usage part in the readme

For sending emails one should use port 1025 and not port 1080.

README.md

@@ -322,7 +322,7 @@ Copy `src/auth.json.sample` to `src/auth.json`. Then, update the username and pa
 
 ### Email / Mailcatcher
 
-View emails sent locally through Mailcatcher by visiting [http://{yourdomain}:1080](http://{yourdomain}:1080). During development, it's easiest to test emails using a third-party module such as [https://github.com/mageplaza/magento-2-smtp](Mageplaza's SMTP module). Set the mailserver host to `mailcatcher` and port to `1080`.
+View emails sent locally through Mailcatcher by visiting [http://{yourdomain}:1080](http://{yourdomain}:1080). During development, it's easiest to test emails using a third-party module such as [https://github.com/mageplaza/magento-2-smtp](Mageplaza's SMTP module). In order to use mailcatcher, set the mailserver host to `mailcatcher` and set port to `1025`. Note that this port is different from the mailcatcher interface to read the emails.
 
 ### Redis