How to Manage Outbound Port 25 Blocking (OP25B)
Asahi Net blocks port 25 to prevent spam email going through.
Outbound Port 25 Blocking (OP25B)
If you are affected by the blocking of port 25, you have to check and change your settings. See the following for reference.
Continue to use a non-Asahi Net outgoing mail server
Use a port other than 25
You can send your email through port 587 (submission port) or port 465 (SMTP over SSL/TLS) of your outgoing mail server.
Contact your mail provider if its outgoing mail server supports port 587 (submission port) or port 465 (SMTP over SSL/TLS).
If you have installed your own outgoing mail server, use port 587 (submission port) or port 465 (SMTP over SSL/TLS) instead of port 25.
If ports other than port 25 are unavailable
If your outgoing mail server does not support port 587 (submission port) or port 465 (SMTP over SSL/TLS), please use Asahi Net’s outgoing mail server or consider getting a fixed IP address if you are subscribed to FLET’S line through Asahi Net.
Use Asahi Net’s outgoing mail server
If you are unable to send email through the outgoing mail server provided by other company, you can consider sending through Asahi Net’s outgoing mail server (e.g., mail.asahi-net.or.jp).
Make sure to authenticate with SMTP using your Asahi Net ID and password when setting up your mailer.
See the following page for how to set up the respective mailer.
- *Use a POP server and its user name/password provided by your email provider.
Use your fixed IP address (IPv4) Provided by Asahi Net
If you are subscribed to a FLET'S line
If you are subscribed to NTT’s FLET’S line, you will be able to send your email through port 25 by applying for the Fixed IP Address Option and getting a fixed IP address.
(The blocking of port 25 will not affect you if you are connected to the internet with Asahi Net’s fixed IP address.)
See the following page for more details on Fixed IP Address Option.
If you are using a relay server
If you have installed an outgoing mail server (i.e., your own server installed by subscribing to Asahi Net’s internet connection service) on a line connected with Asahi Net’s dynamic IP address, and if you wish to send email from such a server, you can do so by making it go through a relay server which is specified by Asahi Net.
- *Asahi Net does not give support on relay server.
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FAQ
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See the following FAQ for other questions on Outbound Port 25 Blocking.