Test Viability of SMTP
reddit / selfhosted

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tibmeister · 2023-12-30 05:43

Anyone got thoughts on a good way to verify if I could host an email
system in my home rig?  Not sure if my ISP actively blocks this type
of activity or not, so would like to come up with a way of testing
this.  I'm mainly having a brain fart on a testing method.  I just
don't want to go through the entire setup then find it was all in
vain.

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adamshand · 2023-12-30 06:13

It's pretty simple to install an SMTP server and then all you  have to
do is try and connect to it on port 25 from the internet.  If that
works, you can run a mail server.

Be aware that most IP addresses you can get from a residential ISP
will be blacklisted and you will have a hard time delivering email to
other servers.

If you don't want to install something, you could contact your ISP's
support and ask them if they block port 25.

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bz386 · 2023-12-30 06:13

First, try to telnet to port 25 on any external email server. If that
works, check your IP on multirbl.valli.org. If it is not blacklisted
anywhere, check if reverse DNS is setup so it matches forward DNS. You
can use mxtoolbox.com. Id you pass all the checks, then you stand a
chance. My guess is you will likely fail at step 1.

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WantonKerfuffle · 2023-12-30 06:26

You may want to use a cheap VPS which only forwards traffic to your
home IP (make sure it's either static or have a way to update your
current home IP on the VPS). That avoids blacklisted IP ranges.

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PossibilityOrganic · 2023-12-30 08:41

You will also have an issue setting ptr records for the ip, and forget
about it if your in a dynamic ip. Email is a pita to host (and have
emails deliver) on a proper server.

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Admirable_Sample2472 · 2023-12-30 12:30

Unfortunately, most IP ranges of major VPS providers are blacklisted.
Deliverability can be a huge hassle when self-hosting SMTP