Temporary (?) VPS setup for Tommy's transition

[infantex]

Thanks for your answer, @wolstech. 

OK, will do that.

Earlier, a few hours after setting the DNS to my VPS's IP, I was able to access mail.zaldivar.mx and log in with one of the mail accounts I created, yes! Just as a note, if I used webmail.zaldivar.mx, I still received the "Service unavailable" error page. After some time, webmail was also working. 

Now, I've added the ns1 A record and deleted the NS records pointing to HelioHost's name servers. I couldn't delete both because I got an error message stating I'd to have at least one NS record, so I edited it to point to ns1.zaldivar.mx. I hope I'm not creating a circular reference.

NEW PROBLEM: I want to read my zaldivar.mx mail from Gmail. When hosted in Tommy, I used POP3 with SSL on port 995 to get it into Gmail. But now, on the Edit Mail Account page in Hestia there's only configuration information for IMAP and SMTP, not POP3. Also there's no option for SSL, only STARTTLS (I must confess I didn't add SSL to the domain when I first created it, I was confused about the offered options - Use Lets Encrypt, Enable HTTPS redirection, Enable HTTP Strict Transport Security - I didn't know what those meant, I added it later - and activated both three options - but still, no SSL option - or POP3 - shows in the email account configuration page). Should I start a new thread for this new question?

EDIT: I found out that you need to activate SSL for the MAIL domain, not (just?) for the (plain/general?) domain. I'll see tomorrow if that worked because, right now, Hestia seems to be frozen, it's been several minutes since I pushed the Save button and I'm still waiting for it to react (it's been slower tonight than this morning but now it's frozen -- the VPS is responsive in the SSH session though, so it's not offline, who knows!)

[wolstech]

You should be able to use imap to connect the email to gmail. POP3 is obsolete (IMAP was its replacement), and a quick Google suggests that Hestia doesn't support it.

As for SSL missing, STARTTLS is basically another name for SMTP over TLS/SSL. The difference in name lies in a single command used during session setup. My experience is that starttls is more common than a straight TLS connection for SMTP. Functionally, once connected they're identical in terms of security after the first command is sent.

Strict transport security and domain SSL is unrelated to email.