MailerZ vs Fastmail is the wrong comparison if you treat them as two forwarders. Fastmail is a hosted mailbox: IMAP, webmail, and calendar on their account — quote https://www.fastmail.com/ for current plans and limits. MailerZ is a receiving hop plus paid authenticated SMTP around Gmail or Outlook. Header From stays intact. Envelope uses SRS. MailerZ is not IMAP. If you need Fastmail’s store, move the store. If you need a hop, keep Gmail and change MX once.
Quick answer for mailerz vs fastmail
Name the store first. If the archive must remain Gmail or Outlook, Fastmail is a migration of mail, clients, and calendar. MailerZ is not. If the archive must become Fastmail, MailerZ will not import PST or IMAP history. Export on their terms.
Price is not the fork. Fastmail’s live seat price versus MailerZ Solo at $40/year is apples to oranges. One is a mailbox. One is a hop with 15 aliases and 100 outgoing. Quote both, then stop pretending the cheaper number wins.
Inbound: one MX owner. Fastmail MX plus MailerZ MX is leftover MX. Some messages land in Fastmail. Some hit MailerZ and Gmail. History looks haunted.
Outbound: Fastmail sends from its store. MailerZ send-as is paid, capped, 550 on unauthorized From. Free has no send-as. Do not keep both SMTP identities in one client.
Neither hop nor store guarantees Gmail Primary. Fastmail’s filtering is theirs. MailerZ destination filtering is Gmail’s. No invented placement SLA.
Transport is still Fastmail — product overview. MailerZ comparisons. MailerZ features. MailerZ pricing.
If Gmail stays the archive, prove MailerZ inbound on Free. If you want Fastmail’s store, quote their live plans and move IMAP — not leftover MX.
Start free — one domainThe real decision
People leave Gmail, buy Fastmail, and keep a forwarder MX “for aliases.” That split is the ticket. Aliases on Fastmail are mailbox aliases. Aliases on MailerZ are hop recipients. Pick the layer.
The other people keep Gmail, buy Fastmail for calendar, and publish Fastmail MX. They just moved inbound away from Gmail. Calendar did not require MX. Read their current calendar-only options if any; do not invent them. If calendar requires the mailbox, you chose a store.
Agencies quoting Fastmail per client plus MailerZ per domain without naming the store will double-bill and dual-publish.
RFPs that say “email solution” without store versus hop will score both vendors as interchangeable. They are not.
When this path is enough
- You can say “store stays Gmail” or “store becomes Fastmail.”
- You will publish one MX set.
- You will quote Fastmail live for IMAP and calendar.
- You accept MailerZ is Mail Box portal webmail, not IMAP.
When this is the wrong ticket
- You want both MX sets as a hybrid.
- You expect MailerZ to grow IMAP.
- You expect Fastmail to become a MailerZ-style HOLD console.
- You want SOC 2 theater from this article.
Technical mail flow
Fastmail MX: senders talk to Fastmail. Mail lives in Fastmail. Clients use IMAP. Quote their setup guides.
MailerZ MX: senders talk to MailerZ. MailerZ forwards to Gmail or Outlook. Clients stay where they are. History is the hop.
A forward from Fastmail to Gmail is Fastmail’s feature, not MailerZ. A MailerZ hop in front of Fastmail means Fastmail is just another destination — possible, but then you have two vendors and still one MX owner (MailerZ). Size that honestly.
DNS leftovers from Google aspmx plus either vendor are still leftovers.
SPF include must match the sender you actually use.
Step-by-step decision path
- Write store or hop One sentence. If you cannot, stop shopping.
- If hop, inventory Gmail aliases and destinations Recreate on MailerZ.
- If store, quote Fastmail live and plan IMAP export Not this hop checklist.
- Publish exclusive MX for that choice Delete the other class’s MX.
- Probe from another mailbox Open the store or the hop history — whichever you bought.
- Configure one outbound path Paid MailerZ SMTP or Fastmail’s SMTP. Not both.
- Keep the other vendor only as a login if you left it Delete its MX.
- Do not promise Calendar on MailerZ Buy a suite or Fastmail if that is the job.
Worked examples
Design pair keeps Gmail, adds MailerZ Solo for hello@ and send-as. Fastmail was a distracting tab. Correct hop.
Privacy-minded founder wants Fastmail as the store. They export Gmail, cut MX to Fastmail, never add MailerZ MX. Correct store.
Hybrid: Fastmail MX plus MailerZ MX. Random empty Gmail. They deleted MailerZ MX and kept the store. Or the reverse. Not both.
Agency used Fastmail for one founder and MailerZ for role addresses on the same domain. Split MX. They moved roles into the store or moved the founder to Gmail plus MailerZ.
Someone asked MailerZ for Fastmail-style conversation view. That is IMAP UI. We do not have it.
If the job is still a hop, size it on the feature and pricing pages.
Open MailerZ featuresFailure modes and proof
| Symptom | Likely cause | Proof |
|---|---|---|
| Split inbound | Both MX | Pick store or hop |
| Missing IMAP | Bought MailerZ expecting webmail | Wrong class |
| Empty MailerZ history | Fastmail or Google MX leftover | Exclusive hop MX |
| Outbound 550 | Free MailerZ or two SMTP hosts | One path |
| Calendar gap | Expected it on the hop | Buy a store/suite |
| Invented Fastmail limits | Blog memory | Quote live |
MailerZ workflow and product boundary
Secuno LLC operates MailerZ. Site: mailerz.net. App: mail.mailerz.net. Envelope SRS only. Header From, Subject, Date, Message-ID, body, and MIME are never rewritten. Not IMAP. Not an open relay.
What MailerZ does
- Accept MX for verified domains.
- Rewrite envelope MAIL FROM with SRS on the forward.
- Leave Header From and MIME intact.
- Hold unknowns on Free. Optional paid FORWARD.
- Paid SMTP from approved identities. Dashboard SPF, DKIM, and DMARC instructions.
- 550 for unauthorized From. Not an open relay.
What MailerZ does not do
- Guarantee Gmail Primary or any inbox placement rate.
- Host IMAP, Calendar, or a Workspace suite.
- Send-as on Free.
- SOC 2, ISO 27001, HIPAA, review counts, or an uptime SLA. Controls: Security and Trust Center.
Plans: pricing. Free $0, 1 domain, 10 aliases, 1 seat, 14-day store, send-as Off, SMTP Off, API Off, unknowns held or rejected. Solo $40/year, 5 domains, 25 aliases, 90-day store, 2,500 outgoing, 20/hour. Starter $8 or $80, 8/50/5, 5,000 outgoing, 40/hour. Business $19 or $190, 25/200/25, 12,000, 60/hour. Agency $39 or $390, 100/500/50, 20,000, 60/hour. Unlimited $99 or $990, uncapped domains and aliases, 180-day store, 100,000 outgoing, 300/hour. Annual Starter, Business, and Agency include two months free versus monthly. Solo is yearly only.
Cost, alternatives, and trade-offs
| Approach | You get | You give up |
|---|---|---|
| MailerZ hop + Gmail store | Keep archive and clients | No IMAP on MailerZ; modest send-as |
| Fastmail store | IMAP, webmail, calendar — quote live | Mailbox migration |
| Both MX | Confusion | Split mail |
| Workspace instead | Google suite | Seats; leftover aspmx if you also hop |
Field notes
Fastmail is not in our /alternative table. Treat their site as source. Nofollow commercial link.
Do not invent Fastmail storage quotas, prices, or privacy certifications.
MailerZ operator is Secuno LLC. Site mailerz.net. App mail.mailerz.net.
If Fastmail is the destination behind MailerZ, Fastmail is just Gmail’s role. Exclusive MailerZ MX. Fastmail’s own MX must go.
Plus addressing habits differ by store. Do not assume MailerZ strips plus tags.
No inbox SLA. No review counts.
Self-send lies for both classes.
Security page for MailerZ controls. Do not clone Fastmail’s compliance page onto ours.
Treat mailerz vs fastmail as a ticket with artifacts, not a vibe. Ask for public MX from two resolvers, a received copy, and MailerZ history before anyone edits TXT.
Write a one-paragraph policy for MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox: inbound versus outbound, what you will not do (dual MX, From rewrite, second SPF), and who owns DNS.
Self-send is invalid for mailerz vs fastmail. Gmail can short-circuit. Use another mailbox and a unique subject.
Leftover MX masquerades as mailerz vs fastmail. Empty history means the hop never ran. Delete aspmx, Microsoft, and registrar MX. Wait TTL.
Free HOLD and missing aliases look like outages. History shows the hold. Create the named local-part. Catch-all FORWARD is paid and optional — not a debugger.
Paid send-as is a different hop. Free cannot send. Unauthorized From is 550 / 550 5.7.1. DNS will not authorize a From the product has not approved.
MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox does not include an inbox placement SLA, review counts, or Primary. Say that early.
Proof packet for mailerz vs fastmail: two-resolver MX, inbound copy with Header From, Authentication-Results, outbound copy if they send, plan name, SMTP line if anything refused.
Retention is 14 days on Free and 90 on paid. Export headers while they live. The destination inbox is the archive.
Agencies should not blend clients in one mailerz vs fastmail thread. Agency limits are 100 domains, 500 aliases, 50 seats, 800 outgoing, 25/hour — still not an SLA.
No SMTP passwords in the mailerz vs fastmail ticket. No invented SOC 2. Controls live on the Security and Trust Center.
If two products share MX, stop adding records. Exclusive MX is a hard stop. mailerz vs fastmail cannot be correct on a split path.
If Header From is rewritten, stop tuning SPF for mailerz vs fastmail. Change the hop. MailerZ will not offer a From-replace control.
If the customer wants Calendar, sell a suite. If they want a hop, sell a hop. MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox is not Exchange.
Hourly and monthly send-as ceilings (50/100/200/400/800 outgoing; 5/10/15/25 per hour) produce refuses that look like mailerz vs fastmail. Read counters.
Null MX plus a real MX is a lie. Remove the lone-dot refuse if you intend to receive.
After any change for mailerz vs fastmail, wait TTL, probe from another mailbox, and store the new received source next to the MX screenshot.
Write mailerz vs fastmail in the subject and the layer in the first sentence: leftover MX, HOLD, destination 550, or TTL. Honest first sentences shrink tickets.
Monthly for mailerz vs fastmail: leftover MX lookup, one external inbound probe, send-as counters if paid. Five minutes. The outage you avoid is a Friday dual-MX restore.
When two vendors disagree about mailerz vs fastmail, believe two resolvers, one received copy, and one history row. Registrar dots lie. Composer UIs lie.
Teach the next hire the MailerZ split before they touch mailerz vs fastmail: envelope may change, Header From must not, Free cannot send, unknowns HOLD, leftover MX is a hard stop.
If mailerz vs fastmail appears in an RFP, answer with published caps and hop evidence. Decline inbox-rate clauses and fake certifications.
Do not bundle unrelated edits with mailerz vs fastmail. Rotating SMTP while republishing MX while enabling FORWARD is how you lose the ability to name the failure.
Field story 1 for mailerz vs fastmail: Design pair keeps Gmail, adds MailerZ Solo for hello@ and send-as. Fastmail was a distracting tab. Correct hop. Keep it in the runbook.
Field story 2 for mailerz vs fastmail: Privacy-minded founder wants Fastmail as the store. They export Gmail, cut MX to Fastmail, never add MailerZ MX. Correct store. Keep it in the runbook.
Field story 3 for mailerz vs fastmail: Hybrid: Fastmail MX plus MailerZ MX. Random empty Gmail. They deleted MailerZ MX and kept the store. Or the reverse. Not both. Keep it in the runbook.
Field story 4 for mailerz vs fastmail: Agency used Fastmail for one founder and MailerZ for role addresses on the same domain. Split MX. They moved roles into the store or moved the founder to Gmail plus MailerZ. Keep it in the runbook.
Field story 5 for mailerz vs fastmail: Someone asked MailerZ for Fastmail-style conversation view. That is IMAP UI. We do not have it. Keep it in the runbook.
For mailerz vs fastmail, “Split inbound” usually means Both MX. Isolate with Pick store or hop. One change at a time.
For mailerz vs fastmail, “Missing IMAP” usually means Bought MailerZ expecting webmail. Isolate with Wrong class. One change at a time.
For mailerz vs fastmail, “Empty MailerZ history” usually means Fastmail or Google MX leftover. Isolate with Exclusive hop MX. One change at a time.
For mailerz vs fastmail, “Outbound 550” usually means Free MailerZ or two SMTP hosts. Isolate with One path. One change at a time.
For mailerz vs fastmail, “Calendar gap” usually means Expected it on the hop. Isolate with Buy a store/suite. One change at a time.
For mailerz vs fastmail, “Invented Fastmail limits” usually means Blog memory. Isolate with Quote live. One change at a time.
Setup step “Write store or hop” for mailerz vs fastmail: One sentence. If you cannot, stop shopping. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “If hop, inventory Gmail aliases and destinations” for mailerz vs fastmail: Recreate on MailerZ. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “If store, quote Fastmail live and plan IMAP export” for mailerz vs fastmail: Not this hop checklist. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “Publish exclusive MX for that choice” for mailerz vs fastmail: Delete the other class’s MX. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “Probe from another mailbox” for mailerz vs fastmail: Open the store or the hop history — whichever you bought. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “Configure one outbound path” for mailerz vs fastmail: Paid MailerZ SMTP or Fastmail’s SMTP. Not both. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “Keep the other vendor only as a login if you left it” for mailerz vs fastmail: Delete its MX. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Setup step “Do not promise Calendar on MailerZ” for mailerz vs fastmail: Buy a suite or Fastmail if that is the job. Skip it and MailerZ vs Fastmail: Forwarding Layer vs Hosted Mailbox becomes next week’s ticket.
Trade-off on mailerz vs fastmail: MailerZ hop + Gmail store gets Keep archive and clients and gives up No IMAP on MailerZ; modest send-as. Write that on the quote.
Trade-off on mailerz vs fastmail: Fastmail store gets IMAP, webmail, calendar — quote live and gives up Mailbox migration. Write that on the quote.
Trade-off on mailerz vs fastmail: Both MX gets Confusion and gives up Split mail. Write that on the quote.
Trade-off on mailerz vs fastmail: Workspace instead gets Google suite and gives up Seats; leftover aspmx if you also hop. Write that on the quote.
Store migration versus hop cutover — do not mix the runbooks
A store migration exports history, moves clients to IMAP, and retrains search. Quote Fastmail’s current import and client docs. A hop cutover recreates aliases, publishes exclusive MX, and leaves Gmail search alone. If your ticket has both checklists, split it. Mixed tickets produce leftover Fastmail MX plus a half-finished IMAP move.
Calendar is a store feature. MailerZ will not grow it. If the real request is calendar plus domain email, Fastmail or Workspace is in class. If the real request is hello@ in Gmail, calendar was a distraction. Write which request won.
Using Fastmail as a MailerZ destination is legal architecture: exclusive MailerZ MX, Fastmail as the inbox like Gmail. Then Fastmail’s own MX must not remain. You are paying a store and a hop. Do that only if you can name why Gmail was not enough as the destination.
Price fights without class waste time. Fastmail’s live seat fee versus MailerZ Free or Solo is not a savings story. One includes IMAP. One includes three aliases and a 14-day hop store. Put class on the spreadsheet or delete the price column.
Client apps differ. Fastmail wants its app or IMAP. MailerZ wants Gmail or Outlook you already run, plus SMTP on paid plans. Training cost is real. Founders who refuse to leave Gmail will sabotage a store move even if Fastmail is “better.”
Privacy narratives cut both ways. A hosted store has a different threat model than Gmail plus a hop. Do not paste Fastmail’s privacy page onto MailerZ or the reverse. Read /security for our controls. Read Fastmail for theirs. Inventing SOC 2 for either side is a fail.
Agencies: one client, one class. A founder on Fastmail and role addresses on MailerZ for the same domain is leftover MX unless MailerZ is the only MX and Fastmail is only a destination. Draw the picture before you bill both.
The bake-off still uses another mailbox as the sender. Self-send into Fastmail or Gmail can hide MX. The class choice does not repeal RFC 5321.
FAQ
What is the safest way to handle mailerz vs fastmail?
Name the store. If Gmail stays, use MailerZ as the hop with exclusive MX. If Fastmail becomes the store, cut MX to Fastmail and quote their live IMAP and calendar docs. Do not publish both MX sets. Do not expect MailerZ to host mailboxes.
Does this require a new mailbox?
MailerZ: no. Fastmail: yes — that is the product. Buying both without naming the store is how leftover MX happens.
Will it work with Gmail or Outlook?
MailerZ yes as destinations. Fastmail replaces them as the store if you cut MX there. You can still read Gmail if you did not move, but inbound follows MX.
What DNS records are involved?
Exactly one inbound MX set for the class you chose. Leftover Google, Fastmail, or MailerZ MX is a hard stop. SPF for the outbound you use.
What should I test before production?
Store sentence written, exclusive MX, probe from another mailbox into the store or hop you bought, one outbound path, no leftover MX.
Key takeaways
- Fastmail is a store. MailerZ is a hop.
- Name the archive first.
- One MX owner.
- Quote Fastmail live. Do not invent prices.
- MailerZ is not IMAP or Calendar.
- Free MailerZ cannot send.
- Hybrid MX is leftover MX.
- Price comparisons without class are noise.
Conclusion and next action
Write “store stays” or “store moves” at the top of the ticket. Every later argument is cheaper. Price tables without that sentence waste a week.
If the store stays, MailerZ is in the right class. Prove inbound on Free. Pay when send-as or retention matters.
If the store moves, go to Fastmail’s docs and run a mailbox migration. Do not keep a forwarder’s MX as a souvenir.
Store or hop
Name the store first
Start free if Gmail remains the archive. Buy Fastmail if you want their IMAP and calendar. Never publish both MX sets.
Review quarterly, or sooner if DNS hosts or dashboard instructions change. Author: MailerZ editorial, Secuno LLC.