Sending mail from a VPS?

Question

Debian

Situation: there is a VPS with a bunch of business card sites, there is almost no mail traffic, the only thing that is sent is all sorts of messages to site owners, for example, “New entry in the guest book”.
At each reboot or restart of network interfaces, the generated hosting provider automatically inserts into /etc/hosts
*.*.*.* vps_id.hostingdomain.tld vps_id
Where instead of * is the server IP, vps_id is the client number. In /etc/hostname, a default value is also inserted at every opportunity. Accordingly, I cannot replace host.
Now the problem: Google began to refuse to accept letters from this server, so it was decided to send all mail from one common [email protected] mailbox, adding an entry to the VPS IP address on the SPF domain.
Tell me, where can I read about setting up sendmail on Debian in conditions where the host name cannot be changed?

This is how Google tells me that my IP address is not authorized to send messages on behalf of vps_id.hostingdomain.tld:

Diagnostic-Code: SMTP; 550-5.7.1 The IP you're using to send mail is not authorized to send email directly to our servers. Please use the SMTP relay at your service provider instead.

Answer 1

Is vps by any chance not on openvz? if on it, then write to the provider, he can register in his panel.

Answer 2

as far as I know, /etc/hosts and /etc/hostname only change on reboot in openvz. Just make a script that exposes the ones you want and add it to rc.local.

Answer 3

/etc/hosts does not affect the host name. On Debian this is affected by /etc/hostname (when running /etc/init.d/hostname.sh).
I do not recommend sendmail to you at all, but I recommend postfix, where you can specify in the config

myhostname = mysite.ru

and let the host do what he wants.

Answer 4

1) Unambiguously replace Sendmail with postfix or exim.
2) Create an account [email protected] and send mail with authorization.
Configuration example: bookmarks.honewatson.com/2008/04/20/postfix-gmail-smtp-relay/