TL;DR: I want to pull emails from 5 accounts on to my homeserver to anti spam them and have my clients pull from there

I currently have like 5 major email accounts on different providers which I use for 100s of accounts on many platforms.

Some of these accounts are very old and come with the added bonus of no spam filter on the free tier.

Now, if you use outlook, you can define anti spam rules there, I know. But since I‘m using many different devices and different mail clients, I can’t be bothered to make anti spam rules for all of them.

So I thought it should be doable to pull all the emails from all my accounts and have them go through anti spam on my home server. Sidenote: I have anti spam on some email providers but I can’t redirect the one address to there as to use that accounts anti spam.

One solution would be to just get rid of this one account but I‘m a little anxious about the consequences since it is my oldest account with unthinkable amounts of accounts linked to it.

Does anyone have a similar scenario or an idea for a solution?

  • @TCB13English
    5•1 year ago

    Dovecot + Postfix + Rspamd can do it. Instead of pulling emails you can simply forward those providers to your homeserver account. You may also setup Postfix in a way that would allow you to use our @gmail @hotmail addresses as “from” addresses / aliases to your local account and it will automatically submit the email through the provider SMTP server when you send something.

    If you really want to pull email instead of setting up forwards (have your server offline more time and whatnot) there are a few options:

    To route the outgoing email through the right provider / external SMTP server based on the “from” address you may configured it like this:

    main.cf:

    smtp_sasl_auth_enable = yes
smtp_sender_dependent_authentication = yes
smtp_sasl_password_maps = mysql:/etc/postfix/virtual/mysql-external-alias-credentials.cf
sender_dependent_relayhost_maps = mysql:/etc/postfix/virtual/mysql-external-alias-relay-hosts.cf
smtp_sasl_security_options = noanonymous

    mysql-external-alias-credentials.cf:

    user = XXXXX
password = XXXXXX
hosts = 127.0.0.1
dbname = mailserver
query = SELECT concat(relay_user, ':', relay_passwd) AS credential FROM `Virtual_Alias_External` WHERE alias='%s' AND active = 1;

    mysql-external-alias-relay-hosts.cf:

    user = XXXXX
password = XXXXXX
hosts = 127.0.0.1
dbname = mailserver
query = SELECT relay_host AS transport FROM `Virtual_Alias_External` WHERE alias='%s' AND active = 1;

    MySQL table structure:

    CREATE TABLE `Virtual_Alias_External` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `alias` varchar(70) NOT NULL,
  `owner` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
  `active` tinyint(1) NOT NULL DEFAULT 0,
  `relay_host` varchar(70) NOT NULL DEFAULT '',
  `relay_user` varchar(70) NOT NULL,
  `relay_passwd` varchar(70) NOT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci ROW_FORMAT=COMPACT;

    Create an entry like this:

    alias: [email protected]
owner: [email protected].org
active: 1
relay_host: [smtp.gmail.com]:587
relay_user:  [email protected]
relay_passwd: your-gmail-password-or-app-password

    Now when you send and email and the from is set as your-emai@gmail.com Postfix will route the email through Gmail’s SMTP server with credential stored on that table. If done correctly (smtpd_sasl_authenticated_header = no) no references to local-email-address@homeserver.example.org will show up on the email headers.