Is there a step-by-step guide for manual email config on the DNS / domain name provider?

[therealwebmaster]

I'm with namecheap. Using their API is not an option.. I have to pay more for it or have more domains names in my account.

[ccfu]

If you know how to set TXT records (which I assume you do if you are running a server), the required SPF, DKIM and DMARC records will be displayed in your Cloudron when you set up email for your domain. Namecheap presumaby also provides a web interface to edit DNS. You will need MX records as well (also shown) and make sure that the PTR record of resolves to the IP your server and matches the hostname you set as mailserver location.

[girish]

@therealwebmaster namecheap API is paid now? I thought it's free?

[girish]

For namecheap, look at their docs - https://www.namecheap.com/support/knowledgebase/article.aspx/434/2237/how-do-i-set-up-host-records-for-a-domain/