Opportunities › Email security and spam filtering for organizations › Proposed app
Gatehouse Mail
Strict inbound mail screening that blocks spoofed, hijacked and unencrypted senders
- Score
- 44
- confidence 58
- Evidence
- 7
- items on the page
- Rivals
- 4
- named in sources
- First version
- 60 d
- estimate
- Type
- Desktop app
- PWA: runs in the browser, installs on Mac and Windows
- Market since
- 1996
- Mature market · AI estimate
ScreensConcept
Desktop app: Security teams monitor dashboards, set policies across domains, and review threat alerts during focused monitoring and response work at a desk. Sample screens on a computer, in the proposed brand. Their numbers are sample data.
Overview
3 domains need attention1,284
About this appAI proposal
Gatehouse Mail sits in front of your mail system and checks every inbound message before it reaches a mailbox. It enforces encrypted delivery between servers, checks SPF, DKIM and DMARC, and holds mail from senders that fail your rules.
It is built for network administrators and small security teams who run mail for their own organization or for customer networks. You set a policy once per domain, then see which senders passed, which were held and why.
The material says big mail providers do not enforce server-to-server encryption and let through spam from paying customers. Gatehouse is strict by default and flags domains that look hijacked.
- Tagline
- Only trusted mail gets through the gate.
- Voice
- StrictPlainCalm
- Why this name
- A gatehouse is where a guard checks who may enter. The name says the product inspects every sender before mail reaches anyone.
In the first version
Members say which features they would use. It tells PWAS what people want; it changes no score.
Enforced encrypted delivery
Require TLS on server connections per domain. Senders that cannot negotiate it are held or rejected, as you choose.
No member yet
SPF, DKIM and DMARC checks
Every message is checked against the sender's published policy. Failures are explained in plain words, not raw headers.
No member yet
Hijacked domain alerts
Flags domains, yours or partners', that suddenly send in new patterns, a sign a botnet may have taken them over.
No member yet
Rotating network grouping
Groups senders that keep changing hosting networks but behave alike, so one rule blocks the whole campaign.
No member yet
Brand identityAI proposal
Check the name against trademark registers before using it.
Palette
#1F5C4AGate Green · primary#F4F1EAPaper · surface#1F2A24Ink · text#D9822BSignal Amber · accent#B3402FAlarm Brick · danger#3B6EA5Slate Blue · data
Typography
Aa
Gatehouse Mail
PricingAI proposal
Verified: Mailgun lists paid plans from $15 to $90 a month plus prices on request; Microsoft 365 lists yearly plans in RON. Tiers follow Mailgun's range. Message limits are untested starting points.
Starter
$15 a month
- 1 domain
- Up to 10,000 messages a month
- TLS enforcement and DMARC checks
- Quarantine review queue
Team
$45 a month
- 5 domains
- Up to 100,000 messages a month
- Hijacked domain alerts
- Weekly threat digest
Network
$90 a month
- 25 domains
- Up to 500,000 messages a month
- Rotating network grouping
What it could be worthEstimate
What a software business making this much sells for today, from real deals. Pick a monthly revenue.
If it makes
Worth about
$194,000
Sale range $132,000 to $263,000
$120,000 a year in revenue
From 87 software businesses listed and sold on Empire Flippers in the last year, revenue vetted by the broker: they sell for about 19× their monthly revenue, most between 13× and 26×.
Measured on profit, the middle deal is 32× monthly net profit: about 2.7 years of profit.
An estimate, not an offer or financial advice. A real price depends on profit, growth, churn, how much of the work is the owner's, and the buyer.
How it would growAI proposal
How the product would reach new customers through its own use, and how the first ones would be found. A plan to test, not a result.
- Built-in loop
- Shared outputs. Quarantine notices and weekly digests go to staff, and rejection messages go to outside senders. These can state that the mail was held by Gatehouse and why, with a link to fix their setup.
- Do they become customers?
- Outside senders are mostly other admins who see failed TLS or DMARC notes, so some may become buyers. Test whether rejection notices produce signups or only support questions.
- First customers
- Small managed IT providers running mail for 5 to 30 small business networks, who handle spam and phishing complaints by hand today.
- Where to reach them
- Hacker News and sysadmin forums: Share write-ups on hijacked domains and unencrypted server connections, with a free domain check linked to a trial.
- MSP communities: Offer a free two-week pilot on one customer domain to managed service provider groups and ask for feedback.
- Direct outreach: Email admins of domains with weak DMARC or no enforced TLS, showing a short report of what their setup allows.
- First milestone
- Five managed IT providers each paying for at least three domains after a two-week pilot.
Why people already pay for this
- VerifiedMicrosoft 365's pricing page lists 4 paid plans, from RON 484.99 to RON 1099.99 a year
- Public claimMajor email providers do not enforce SSL from server to server and allow spam from paying customers
- Public claimBotnet campaigns have taken over domains that fall through security cracks, with actual owners unaware their domains are spamming others
- Public claimSpam increasingly comes from rotating ASNs associated with growth marketing operations
- AI inference
Tech stack
Every proposal builds on the same PWA base, installable from the browser on any phone or computer. Dashed boxes are what this app adds.
- AppNext.js and TypeScript
- PWAManifest and service worker
- UITailwind CSS
- Data and authSupabase Postgres
- PaymentsStripe
- EmailResend
- HostingVercel
- This app · Mail gatewayInbound SMTP relay with TLS policy supportMail must be received, checked and forwarded before delivery. Vercel and Supabase cannot run an SMTP server.
- This app · Mail authentication checksSPF, DKIM, DMARC verification librariesNeeded to score each message against the sender's published policy.
RisksAI inference
- TechnicalRunning a mail gateway means high availability. Downtime or bad rules can delay or lose customers' mail, so retries and failover are required from day one.
- CommercialCustomers may stay with their current provider's built-in filtering. Whether admins pay for a stricter extra layer is unproven.
- RegulatoryHolding and reading customers' mail creates privacy duties, including data processing terms and retention limits, that vary by country.
- DataDetecting hijacked domains and rotating networks needs good sender reputation data. A small team may lack the volume to match it at first.
- TechnicalStrict TLS enforcement will block some legitimate senders. False positives could erode trust unless override tools are easy.
Everything marked AI proposal or AI inference was written by a model from the evidence on the opportunity page. The proposed name must be checked against trademark registers before it is used.