I'm trying to send mail on my server which on located on vps in Google Cloud. I can telnet to gmail's SMTP both 587/465 but i can't connect via telnet to Yandex.
It's stucking on Trying ....
# telnet mail.yandex.ru 587
Trying 213.180.193.125...
I opened all ports (both tcp and udp) but still same.