Selectel, Ubuntu 10.04, stubborn sendmail?

Question

send mail

In the light of recent nightmares on Klodo, I urgently transferred an important site to selectel. DNS-s have not been updated yet, I check the operation of the site on the IP address.
The virtual host config contains:
php_admin_value sendmail_path "/usr/sbin/sendmail -t -i -f [email protected]"
sendmail with default config, from repo.
Apache MPM-ITK, on ​​the nginx front from turnips (0.7.65).
The return zone at selectel is registered.
When a script is executed, which includes sending a letter (via the standard php mail function), everything is thoughtful for a very long time, nginx throws out a 504 error, and for some time everything slows down hard. The letter eventually arrives normally.
Is it because of non-updated DNS and IP access, or do I need to configure something in sendmail?

Answer 1

try in the console with the mail utility to send a letter will it be the same?