Home email server?

[Mr Technician]

I've always wanted to run a home email server on a raspberry pi but always assumed it would fail due to ISP port blocking. I'm currently running Comcast which blocks port 25, but they do offer SMTP relay servers. Furthermore, port 25 isn't used anymore anyway from what I can see. What I'm wondering is if this would be feasible as a fun experiment. Would I actually be able to send and receive email?

 

I also found this website: https://www.authsmtp.com/faqs/faq-4.html

 

Xfinity blocked ports list: https://www.xfinity.com/support/articles/list-of-blocked-ports

 

I just need to grab a domain from domain.com or namecheap first.

[Acedia]

How do you figure port 25 is not used anymore? SMTP/TLS is using 25/tcp.

[ChairSpelledWrong]

I suppose that having your own email server would be a fun experiment to take back your privacy and maybe make things a little easier as your using a custom domain name, although it still costs more than having a free online solution like proton mail or riseup.

[Mr Technician]

1 hour ago, TheChairSalesman said:

I suppose that having your own email server would be a fun experiment to take back your privacy and maybe make things a little easier as your using a custom domain name, although it still costs more than having a free online solution like proton mail or riseup.

I’ve never heard of proton or riseup but I will take a look.

[ddennis002]

21 hours ago, ThatFlashCat said:

I've always wanted to run a home email server on a raspberry pi but always assumed it would fail due to ISP port blocking. I'm currently running Comcast which blocks port 25, but they do offer SMTP relay servers. Furthermore, port 25 isn't used anymore anyway from what I can see. What I'm wondering is if this would be feasible as a fun experiment. Would I actually be able to send and receive email?

 

I also found this website: https://www.authsmtp.com/faqs/faq-4.html

 

Xfinity blocked ports list: https://www.xfinity.com/support/articles/list-of-blocked-ports

 

I just need to grab a domain from domain.com or namecheap first.

I have done this in the past probably back in 2009 before I had alot more experience, and it was fun I used an exchange server over the mail server build into windows server. You get alot more options not to mention beable to filter out spam ect.

I had a dynamic IP and run DynDNS on router then used relays to so it wouldn't get blocked by google, yahoo ect for not having static IP.

[Mikensan]

Port 25 is definitely still used, but as you already discovered, your ISP offers relays - I would take advantage of that. The goal is to limit how many emails per minute you can send, otherwise they don't do anything else to your traffic. If you have a business plan you can call them and have it unblocked.

 

I'm not aware of any free dynamic dns solutions that offer MX records, so you may need to buy a DNS name from a registrar if you don't already have one. (you can find some as cheap as $5/yr)

 

You'll also need to setup some custom DNS entries (SPF record) to help mail servers trust your domain a little more (not a guarentee). Otherwise your mail may end up in peoples' spam folders (partly why you see so many companies say "check your spam folder").

 

The hardest part is battling incoming spam. Definitely have one mailbox for free website signups (honestly I would use gmail for this so they don't get your domain name) and another for paid and professional use.

 

I think it's worth the time as a hobby / project. Definitely try to get encrypted/secure mail working to familiarize yourself with that. Also SSL SMTP doesn't actually "use" port 25, it simply announces to the mail server over port 25 to switch to SSL (467). So you can use SMTP SSL without 25, it's simply a legacy feature left behind to offer more compatibility.

 

Honestly if the destination server won't accept encrypted communication I'd expect it to be old and comprimised, better off not sending mail there.

[Mr Technician]

Just now, Mikensan said:

Port 25 is definitely still used, but as you already discovered, your ISP offers relays - I would take advantage of that. The goal is to limit how many emails per minute you can send, otherwise they don't do anything else to your traffic. If you have a business plan you can call them and have it unblocked.

 

I'm not aware of any free dynamic dns solutions that offer MX records, so you may need to buy a DNS name from a registrar if you don't already have one.

 

You'll also need to setup some custom DNS entries (SPF record) to help mail servers trust your domain a little more (not a guarentee). Otherwise your mail may end up in peoples' spam folders (partly why you see so many companies say "check your spam folder".

 

The hardest part is battling incoming spam. Definitely have one mailbox for free website signups (honestly I would use gmail for this so they don't get your domain name) and another for paid and professional use.

 

I think it's worth the time as a hobby / project. Definitely try to get encrypted/secure mail working to familiarize yourself with that. Also SSL SMTP doesn't actually "use" port 25, it simply announces to the mail server over port 25 to switch to SSL (467). So you can use SMTP SSL without 25, it's simply a legacy feature left behind to offer more compatibility.

 

Honestly if the destination server won't accept encrypted communication I'd expect it to be old and comprimised, better off not sending mail there.

Yeah I need to get a domain for this I'm just not familiar with domain registrars. I wouldn't use this server for much, all of my accounts are connected to my gmail and I have no intention of switching them to my own mail server. It's really just because I can more than anything else.

[Mikensan]

17 minutes ago, ThatFlashCat said:

Yeah I need to get a domain for this I'm just not familiar with domain registrars. I wouldn't use this server for much, all of my accounts are connected to my gmail and I have no intention of switching them to my own mail server. It's really just because I can more than anything else.

I've used google domains and name cheap, no problems with either and both support dynamic dns updates through an agent. If you have pfsense, it natively supports both.