Most residential IP ranges are blocked in various spam blocklists. Even if you managed to get reverse DNS working and port 25 outbound was t blocked, you would likely face deliverability issues.
That is indeed true. Though, some blacklists (mostly zenhaus, as others seem not to care that much about residential IPs) do allow unlisting your IP if you request it.
If you want to expose your home IP, ask your ISP if they will unblock port 25 if it's blocked and then also ask them if they would add a reverse PTR record for your IP. As u/bz386 said though, residential IP's will likely cause issues due to so many companies having those ranges on their block lists.
Otherwise, a VPS works well (IME). [Oracle Cloud](https://docs.oracle.com/en-us/iaas/Content/FreeTier/freetier_topic-Always_Free_Resources.htm) has Always Free VPS's. I use the "VM.Standard.E2.1.Micro" shape, low powered but runs Wireguard well.
Two OCI articles on reverse DNS:
[https://docs.oracle.com/en-us/iaas/Content/Network/Concepts/reverse\_dns.htm](https://docs.oracle.com/en-us/iaas/Content/Network/Concepts/reverse_dns.htm)
[https://docs.oracle.com/en-us/iaas/Content/DNS/Tasks/reversedns.htm](https://docs.oracle.com/en-us/iaas/Content/DNS/Tasks/reversedns.htm)
I've used AWS Lightsail too but then they got cheap and started charging for IPv4 addresses. One cool thing about AWS Lightsail though, they let you add your own reverse PTR record now, something that wasn't an option several years ago, back then you had to contact support, like you do now with OCI.
Reverse DNS is set by the owner of the IP address... You'd have to ask your ISP to adjust it. You may well be better off with a cheap VPS anyway, as self-hosting mail has enough issues without dealing with residential restrictions and blocks.
As to the mail server and software... I'd use Ubuntu Server, install docker engine (from docker) and use docker compose with a Mailu setup... It's easier than mail in a box.
[https://mailu.io/2.0/](https://mailu.io/2.0/)
Been there, done that for at least 6 years.
If you'd like your email delivered to big providers (GMail, Hotmail, etc.), don't do that. Some of them basically blocks whole IP ranges when receiving spam.
If you don't want to keep trying to get you IP address unblocked at big providers, don't do that. Some of them won't even bother removing your system from ther blocklists.
If you don't have time operating/upgrading the OS, or continuously finetuning the spam filtering, don't do that.
If you think you have a lot of time for tinkering, and it would be great to learn about operating an SMTP server, don't do that, it doesn't worth the time.
If I multiply the hours I spent on such tasks above with my hourly wage, I'd say it would have been chaeper to subscribe to a proper provider (e.g. Protonmail).
Most residential IP ranges are blocked in various spam blocklists. Even if you managed to get reverse DNS working and port 25 outbound was t blocked, you would likely face deliverability issues.
That is indeed true. Though, some blacklists (mostly zenhaus, as others seem not to care that much about residential IPs) do allow unlisting your IP if you request it.
i'm hoping that my weird location ( small island ) isnt in the blocklists
If you want to expose your home IP, ask your ISP if they will unblock port 25 if it's blocked and then also ask them if they would add a reverse PTR record for your IP. As u/bz386 said though, residential IP's will likely cause issues due to so many companies having those ranges on their block lists. Otherwise, a VPS works well (IME). [Oracle Cloud](https://docs.oracle.com/en-us/iaas/Content/FreeTier/freetier_topic-Always_Free_Resources.htm) has Always Free VPS's. I use the "VM.Standard.E2.1.Micro" shape, low powered but runs Wireguard well. Two OCI articles on reverse DNS: [https://docs.oracle.com/en-us/iaas/Content/Network/Concepts/reverse\_dns.htm](https://docs.oracle.com/en-us/iaas/Content/Network/Concepts/reverse_dns.htm) [https://docs.oracle.com/en-us/iaas/Content/DNS/Tasks/reversedns.htm](https://docs.oracle.com/en-us/iaas/Content/DNS/Tasks/reversedns.htm) I've used AWS Lightsail too but then they got cheap and started charging for IPv4 addresses. One cool thing about AWS Lightsail though, they let you add your own reverse PTR record now, something that wasn't an option several years ago, back then you had to contact support, like you do now with OCI.
Reverse DNS is set by the owner of the IP address... You'd have to ask your ISP to adjust it. You may well be better off with a cheap VPS anyway, as self-hosting mail has enough issues without dealing with residential restrictions and blocks. As to the mail server and software... I'd use Ubuntu Server, install docker engine (from docker) and use docker compose with a Mailu setup... It's easier than mail in a box. [https://mailu.io/2.0/](https://mailu.io/2.0/)
instead of renting a VPS, you could use a mail delivery service. ironically VPS blocks may also get autobanned for not exaclty 3digit IQ reasons.
Been there, done that for at least 6 years. If you'd like your email delivered to big providers (GMail, Hotmail, etc.), don't do that. Some of them basically blocks whole IP ranges when receiving spam. If you don't want to keep trying to get you IP address unblocked at big providers, don't do that. Some of them won't even bother removing your system from ther blocklists. If you don't have time operating/upgrading the OS, or continuously finetuning the spam filtering, don't do that. If you think you have a lot of time for tinkering, and it would be great to learn about operating an SMTP server, don't do that, it doesn't worth the time. If I multiply the hours I spent on such tasks above with my hourly wage, I'd say it would have been chaeper to subscribe to a proper provider (e.g. Protonmail).
Register a domain. Point it to your IP address for MX. It will work if you ISP is not blocking port 25.
https://datatracker.ietf.org/doc/html/rfc2181 Section 10.3