No valid SPF? No access.
If the sending server cannot prove it is allowed to send mail for that domain, it does not get to wander into your inbox wearing a fake mustache.
Spam handling • Authentication checks • Firewall-level attitude
Your inbox is not a garbage dump.
Inboxatron.Email does not treat spam like an adorable little inconvenience. If mail shows up without proper authentication, bad signatures, or starts acting like a bulk-message firehose, we do not gently tuck it into a folder and wish you luck. We stop it at the door.
mailguard@inboxatron:~$ check-spf suspicious.example
SPF failed. Door remains closed.
mailguard@inboxatron:~$ verify-dkim bulkblast.invalid
Bad DKIM. Nice try, clown cannon.
mailguard@inboxatron:~$ spamassassin --watch
Mass message pattern detected.
mailguard@inboxatron:~$ firewall --block-source
Connection denied. Inbox remains civilized.
The gate is rude for a reason.
Spam filtering works better when garbage does not get invited inside first. Inboxatron.Email checks the basics early, because pretending broken mail is fine is how inboxes become landfills.
Bad DKIM? Also no access.
If the signature fails, the message fails. We are not here to babysit forged mail with confidence issues.
SpamAssassin watches the pattern.
When a sender starts acting like a mass-message firehose, SpamAssassin helps identify the blast before it turns your inbox into a dumpster behind a coupon printer.
When spam gets loud, the firewall gets louder.
Some providers tag spam and make it your problem. That is adorable. When we see repeat abuse, bulk bombardment, or obvious trash behavior, we block the source at the firewall. Does not matter if you started this with a bad sign up or somone is trying to mail bomb you. It gets blocked.
1
Sender connects
Mail shows up and claims it is legitimate. Sure it does. So does every scammer with a logo and a dream.
Verify
2
Authentication is checked
SPF and DKIM need to make sense. If they do not, that mail is not getting a tour of the building.
Reject
3
Spam behavior is detected
SpamAssassin catches the mass-message nonsense and flags the sender as a problem, even if YOU are the problem, not a misunderstood artist.
Escalate
4
Firewall block
Once a sender crosses the line, we block connections at the firewall. No more retries. No more resource drain. No more nonsense.
Blocked
Fair warning: if you run a misconfigured mail server, want to blast bulk mail like it is 2003, or think authentication is optional, Inboxatron.Email may not be your friend. We are fine with that.
Cleaner mail. Fewer dumpster fires.
Inboxatron.Email is $2/month or $20/year. Secure IMAP only. Bring your own client. Spam gets treated like spam, not like a valued guest with poor manners.