Roundcube SMTP 451 temporary lookup failure

[mrobot]

Hello guys, i have fresh install of sentora.
I configured all settings as on my old server. But when i login to roundcube and try to send email, the windows is saying Error SMTP (451): Cant add recepient "test@stacknet.eu" (4.3.0 <test@stacknet.eu>: Temporary lookup failure)

I dont know where is problem. Passwords to mysql is OK, connection to SMTP server looks ok....

I tried to connect to SMPT server via putty (telnet 25) and when i want manualy send email via console, the server is saying some error.

I think probably DNS? Routes? What do you think?

[TGates]

According to intoDNS, you do not have MX records for the domain: https://intodns.com/stacknet.eu

[mrobot]

I dont know how is it possible, im using cloudflare and there is two mx records configured.. i modified it and try to wait for update...

BUT: even i technicaly dont have configured mx records for my domain, i must be able to send email to gmail or to other server right?

MX records is for incoming mails right?

[TGates]

Yes, MX if for incoming mail.

Your post on serverfault needs to be edited! It is showing your roundcube DB password!! Along with some other information that should remain hidden!

[mrobot]

Thank for you for your attention. But it does not matter, after I fix this issue i will reinstall the whole server. First i must understand what is making this error, because this is clean instalation too...

As you writed MX is for incoming mails: I have problem with both, when i try to send email from gmail to my server the server responds in mail
451 4.3.0 <jakub@stacknet.eu>: Temporary lookup failure

When i try to send email from my server to gmail or somewhere else the roundcube cant send because is saying some error.

[TGates]

I'm not sure how Cloudflare works.. I use an SMTP relayer to send mail (mailjet.com) and my own DNS in Sentora.
Me.B may be able to help you with that.

[Me.B]

https://intodns.com/stacknet.eu

see the red part you didn't setup any MX for that domain. So you need to setup MX entries that point to a CNAME DNS entry resolving to server IP.

Example
MX point to mail.stacknet.eu
and mail.stacknet.eu A record type and resolves to server ip.

M B