Outbound SMTP connections timing out from Railway service
rodrigo-bj-remax
PROOP

a month ago

Hello Railway Support Team,

I have a Passbolt service running on Railway and need to send emails through Mailgun SMTP.

However, outbound SMTP connections from inside the container are timing out. I tested multiple SMTP providers and ports directly from the running container:

smtp.mailgun.org:587 → Connection timed out

smtp.mailgun.org:2525 → Connection timed out

smtp.mailgun.org:465 → Connection timed out

smtp.gmail.com:587 → Connection timed out

smtp.sendgrid.net:2525 → Connection timed out

Example test result:

php -r '$s=@stream_socket_client("tcp://smtp.mailgun.org:2525",$e,$m,10); var_dump((bool)$s,$e,$m);'

bool(false)

int(110)

string(20) "Connection timed out"

php -r '$s=@stream_socket_client("tcp://api.mailgun.net:443",$e,$m,10); var_dump((bool)$s,$e,$m);'

I enabled Outbound IPv6 as well, but smtp.mailgun.org does not return an IPv6/AAAA record.

Could you please verify whether there is any outbound SMTP/egress restriction, firewall rule, routing issue, or IP-level filtering affecting TCP ports 465, 587, and 2525 from my Railway service/region?

My application depends on authenticated SMTP for Passbolt invitations, password recovery, and notifications.

Thank you.

Solved

2 Replies

Railway
BOT

a month ago

Outbound SMTP is only available on the Pro plan and above; it is disabled on Free, Trial, and Hobby plans. For sending emails from your application, please use a dedicated email service that provides an HTTPS API (Mailgun itself offers one). More details are in our outbound networking docs.


Status changed to Awaiting User Response Railway 29 days ago


Railway

Outbound SMTP is only available on the Pro plan and above; it is disabled on Free, Trial, and Hobby plans. For sending emails from your application, please use a dedicated email service that provides an HTTPS API (Mailgun itself offers one). More details are in our [outbound networking docs](https://docs.railway.com/networking/outbound-networking).

rodrigo-bj-remax
PROOP

a month ago

I performed the procedure and the ports failed

root@a0a986e5cba7:/usr/share/php/passbolt# SMTP_HOST="$smtp.mailgun.org" bash -c '

for port in 25 465 587 2525; do

timeout 1 bash -c "</dev/tcp/$SMTP_HOST/$port" 2>/dev/null && \

echo "$SMTP_HOST port $port reachable" || \

echo "$SMTP_HOST port $port unreachable"

done

'

.mailgun.org port 25 unreachable

.mailgun.org port 465 unreachable

.mailgun.org port 587 unreachable

.mailgun.org port 2525 unreachable

root@a0a986e5cba7:/usr/share/php/passbolt# SMTP_HOST="smtp.mailgun.org" bash -c '

for port in 25 465 587 2525; do

timeout 1 bash -c "</dev/tcp/$SMTP_HOST/$port" 2>/dev/null && \

echo "$SMTP_HOST port $port reachable" || \

echo "$SMTP_HOST port $port unreachable"

done

' smtp.mailgun.org port 25 unreachable

smtp.mailgun.org port 465 unreachable

smtp.mailgun.org port 587 unreachable

smtp.mailgun.org port 2525 unreachable

root@a0a986e5cba7:/usr/share/php/passbolt#


Status changed to Awaiting Railway Response Railway 29 days ago


Status changed to Solved rodrigo-bj-remax 29 days ago


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