smtp connect failed

[hwp994108018]

Hello,
I have mailwizz installed, and have a remote smtp server ready, it works, and I have tested it via https://www.gmass.co/smtp-test.
However, when I add Delivery Server, the system displays an error “

• Connection could not be established with host IP :stream_socket_client(): Unable to connect to tcp://IP:25 (Connection timed out)
  Log data:
  ++ Starting Swift_SmtpTransport
  !! Connection could not be established with host IP :stream_socket_client(): Unable to connect to tcp://IP:25 (Connection timed out) (code: 0)

”

 

[twisted1919]

Most likely your hosting is blocking outgoing connections, this is why you could connect to the same smtp server from outside your host but not from within. Contact them and ask them about it.

 

[hwp994108018]

PING google.com (142.250.217.238) 56(84) bytes of data.
64 bytes from pnlgaa-ay-in-f14.1e100.net (142.250.217.238): icmp_seq=1 ttl=118 time=1.24 ms
64 bytes from mia07s62-in-f14.1e100.net (142.250.217.238): icmp_seq=2 ttl=118 time=1.16 ms
64 bytes from pnlgaa-ay-in-f14.1e100.net (142.250.217.238): icmp_seq=3 ttl=118 time=1.39 ms
64 bytes from pnlgaa-ay-in-f14.1e100.net (142.250.217.238): icmp_seq=4 ttl=118 time=1.15 ms
64 bytes from mia07s62-in-f14.1e100.net (142.250.217.238): icmp_seq=5 ttl=118 time=1.18 ms
64 bytes from pnlgaa-ay-in-f14.1e100.net (142.250.217.238): icmp_seq=6 ttl=118 time=1.19 ms
64 bytes from mia07s62-in-f14.1e100.net (142.250.217.238): icmp_seq=7 ttl=118 time=1.22 ms
64 bytes from mia07s62-in-f14.1e100.net (142.250.217.238): icmp_seq=8 ttl=118 time=1.20 ms
^C
--- google.com ping statistics ---
8 packets transmitted, 8 received, 0% packet loss, time 7011ms

This seems to have nothing to do with the outgoing block.

 

[twisted1919]

You need to test the connection to the smtp hostname using the port 25, so maybe something like

telnet my-smtp-ip 25

ping is really useless in this case, it does not tell you if you can or cannot connect on a certain host and port combo.

 

[hwp994108018]

thanks for your help, you are right, the provider block the outgoing connection.

another question: how to speed up sending
I've already optimized Mailwizz via the following links, but the sending speed is still slow. the vps for mailwizz: 4 vcpu, 8G ram, 160G ssd

Email Delivery Settings: Performance Impact Analysis

Understanding email delivery settings and how they impact performance

www.mailwizz.com

MailWizz For High Volume Email Sending

Sending a large volume of emails is always a challenge and depending on your data size and infrastructure, MailWizz is designed to meet your expectations.

www.mailwizz.com

Debug send campaigns command | MailWizz Email Marketing Documentation

Debug send campaigns command

www.mailwizz.com

Logging delivery took: 0.00284
[2026-03-25 13:53:21] - Checking if the server is over quota...
[2026-03-25 13:53:21] - Preparing the entire email...
[2026-03-25 13:53:21] - Parsed the tracking links from the html email content in 0.00029 seconds.
[2026-03-25 13:53:21] - Using delivery server: mail.example.com (ID: 4).
[2026-03-25 13:53:21] - Logging into delivery server usage log took: 0.0015
[2026-03-25 13:53:21] - Sending the email to the delivery server...
[2026-03-25 13:53:21] - Communication with the delivery server took: 2.65865
[2026-03-25 13:53:21] - Sending response is: OK
[2026-03-25 13:53:21] - Sending OK.

 

[twisted1919]

This is your problem:
[2026-03-25 13:53:21] - Communication with the delivery server took: 2.65865
You have slow smtp server(s). You can try to enable PCNTL for faster sending, but with almost 3 seconds per send, it will still be slower than you might expect.