Best ImprovMX alternative for Gmail-based teams

Quick answer for an ImprovMX alternative

The best ImprovMX alternative for a team that already lives in Gmail is another custom-domain forwarder plus, when replies must show the domain, authenticated SMTP. MailerZ is one product in that class: inbound MX, envelope SRS only, Header From never rewritten, delivery history, a recovery window, and paid send-as. It is not Google Workspace. It is not IMAP. It is not an open relay.

ImprovMX is the closest commercial class, not a villain. Compare current ImprovMX packaging on their site rather than from memory: ImprovMX — product documentation. This page does not copy their price list. It explains the job a Gmail team is actually buying: receive on a domain, land in existing inboxes, keep evidence when a hop fails, and send as the domain without provisioning Workspace seats.

The safest cutover is sequential. Export or photograph every alias and destination. Recreate them on MailerZ while the old MX is still live. Lower TTL if you can. Publish MailerZ MX. Delete leftover ImprovMX, Google, and registrar MX. Probe from a mailbox that is not the destination. Only then attach Gmail Send mail as. The field map for that last step is send as your custom domain from Gmail without Workspace.

MailerZ Free is one domain, three aliases, one seat, a 14-day store, send-as disabled, SMTP and API disabled, and unrouted mail held or rejected only. That is enough to prove inbound. It is not enough if the acceptance test includes “recipient sees our domain on the reply” or if you have more than three local-parts. Paid plans add a 90-day store and send-as within published limits. Solo is $40 per year. Starter is $8 monthly or $80 yearly. Business is $19 or $190. Agency is $39 or $390. Unlimited is $99/month or $990/year. Confirm numbers on MailerZ pricing.

If you want the side-by-side product page rather than this setup essay, use MailerZ as an ImprovMX alternative and the cutover notes on migrate from ImprovMX. Those pages do not replace a two-direction test.

The user problem and the decision criteria

Gmail-based teams shop for an ImprovMX alternative for boring reasons. They want delivery evidence when a customer swears they sent mail. They want leftover MX called out as a hard stop. They want send-as on the same vendor that receives. They hit a plan ceiling. They want Header From left alone so filters and replies do not rot. Those are operational complaints, not a request for Calendar seats.

The wrong reaction is to buy Workspace because “email is email.” Workspace is a hosted mailbox suite. You already have Gmail. The right reaction is to name the jobs you will test on week one.

Stay on ImprovMX if it already meets those tests and switching would be theater. Switch if you need the MailerZ evidence model, send-as on the same layer, or plan shape on MailerZ features. Do not switch because a blog used the word “best” as a trophy.

Technical mail flow

Internet mail does not know your vendor brand. IETF RFC 5321 — Simple Mail Transfer Protocol is the transport standard. The sender looks up MX, delivers, and is done. An ImprovMX alternative only changes which host answers and what happens after SMTP 250: store, forward, log, and later send.

Inbound on MailerZ

A customer sends to hello@yourdomain.com. If MailerZ MX is the only published answer, the message arrives there. The edge checks verification and whether the recipient matches an alias, a route, or catch-all policy. Unknown addresses on Free are held. Paid plans can forward unknown recipients when you enable that. Holding unknown mail is the safer default for a team that used a short alias list on ImprovMX.

MailerZ stores required content and metadata before it returns 250. Then it forwards to the verified Gmail destination. Header From stays the original sender. Envelope MAIL FROM may use SRS. Delivery history records the destination response. Gmail can still file the copy in spam. That is Gmail’s decision.

Outbound is a second product

Forwarding inbound does not send as the domain. Gmail Send mail as needs an SMTP server allowed to use that identity. On MailerZ that credential exists on paid plans only. You copy host, port, username, and generated password. MailerZ authenticates, checks the From identity, applies hourly and monthly limits, and submits. Unhosted or unauthorized recipients get 550. MailerZ is not an open relay.

SPF, DKIM, and DMARC help receivers evaluate authorization. They do not place mail in Primary. IETF RFC 7208 — Sender Policy Framework (SPF), IETF RFC 6376 — DomainKeys Identified Mail (DKIM), and IETF RFC 7489 — Domain-based Message Authentication, Reporting, and Conformance (DMARC) are the protocol texts. Publish the values the dashboard shows. Alignment still depends on the visible From matching what those records authorize.

Recovery storage is 14 days on Free and 90 days on paid plans. It is not a second Gmail and not a compliance vault. If you needed ImprovMX only as a pipe and never opened logs, you can ignore the window until a hop fails. When it fails, the window is the reason you switched.

Teams underestimate the Gmail side of the hop. Filters that once matched an ImprovMX Received header may hide MailerZ forwards. A catch-all that used to dump typos into a shared inbox becomes a held message on Free. Shared destinations that were never verified stall the first probe. None of those are “MailerZ lost mail.” They are leftovers from a different operating model. Walk the destination inbox the same day you cut MX: spam, promotions, filters, and the address that actually completed verification.

Seats are not mailboxes. A Starter plan with five seats means five people can operate the MailerZ account, not five new Gmail users. The team still reads mail where they already read mail. If someone on the team needs a Workspace login, Calendar, and a hosted archive, that person is a suite seat. Do not buy Agency because one founder wanted Drive. Split the roster: who needs a route, who needs a mailbox.

Step-by-step setup and decision path

This is the ImprovMX alternative setup path for a Gmail team. Recreate first. Cut MX second. Cancel the old account last.

1. Inventory aliases, destinations, and catch-all

   List every local-part that still receives production mail. Note destinations that are shared Gmail inboxes versus personal ones. Note whether unknown recipients were forwarded or dropped. MailerZ Free holds unknown mail and allows three aliases. Count before you assume a one-click import exists. It does not.

2. Add the domain on MailerZ and verify TXT

   Use the root domain, not a mailbox and not https://. Publish the unique verification TXT. Receiving stays off until that check passes. Do this while ImprovMX MX is still live so you are not racing DNS.

3. Recreate aliases and verify destinations

   Map each role address to the same Gmail destinations the team already uses. Complete destination verification. Do not create loops. Shared inboxes should be explicit aliases, not a hope that catch-all will sort them.

4. Publish MailerZ MX and delete leftovers

   Copy exact hosts and priorities. Then look at the public MX set. Old ImprovMX hosts beside MailerZ hosts split inbound traffic. Leftover Google Workspace MX does the same. Treat mixed MX as a hard stop. Query two resolvers. Use the migration planner if you want the sequencing on one page.

5. Prove inbound from a different mailbox

   Send a uniquely titled message from an unrelated provider into each critical alias. Open Gmail. Confirm the visible sender. Open MailerZ history. Self-send from the team Gmail account can short-circuit and hide a bad cutover.

6. Upgrade only if send-as is in the acceptance test

   Free stops here. When replies must leave as the domain, move to Solo or another paid plan, create the SMTP credential, and add Gmail Send mail as. Do not paste Google passwords into the SMTP form.

7. Send to a second external inbox

   Check visible From, reply path, and outbound history. Inbox placement on the far side is still their filter. Plan limits: Solo 5 send-as per hour and 100 outgoing per month; Starter 10/hour and 200; Business 15/hour and 400; Agency 25/hour and 800.

8. Cancel the old forwarder after a quiet week

   Keep rollback MX written down. Do not delete the ImprovMX account the hour the first test lands. Cached MX and a forgotten alias are cheaper to fix if the old host can still be republished. Write the previous hosts in the same note as the new ones. If a regional resolver still answers the old set tomorrow, you will want that string without hunting email archives.

Failure modes and proof

Most “the alternative is broken” reports on day one are leftover MX, an alias you forgot to recreate, or a self-send test. Work the evidence.

Proof is a sanitized destination header block plus the MailerZ event with timestamp and remote response. Do not send SMTP passwords to support. Do not publish verification tokens. Inbox placement is not proof of a correct MX set.

DNS-only diagnostics live on troubleshooting. Failed hops after a clean MX set are a delivery recovery problem.

MailerZ workflow and product boundary

MailerZ is a custom-domain email delivery layer operated by Secuno LLC. Point MX at MailerZ. Mail for a hosted, verified domain can land in Gmail or Outlook. Paid plans add authenticated SMTP. The live site is mailerz.net. The app is mail.mailerz.net.

Positioning for this article: MailerZ is a focused forwarding plus SMTP layer around the inbox you already use. That is the ImprovMX-class job. It is not a suite alternative unless you were wrongly treating ImprovMX as Workspace.

What MailerZ does in this workflow

• Accept inbound mail for verified domains and configured recipients.
• Preserve Header From on the forward into Gmail.
• Hold or forward unknown recipients according to plan and settings.
• Store messages for 14 days on Free or 90 days on paid plans.
• Send through authenticated SMTP from approved identities on paid plans.
• Record delivery history for inbound and outbound hops.
• Surface leftover MX as a diagnostic hard stop, not a health score.

What MailerZ does not do

• Import ImprovMX aliases automatically.
• Replace Gmail with IMAP or webmail.
• Rewrite header From, Subject, Date, Message-ID, body, or MIME.
• Offer send-as on Free.
• Promise inbox placement, uptime SLAs, or review counts.
• Claim SOC 2, ISO 27001, or HIPAA. Controls live on Security and Trust Center.
• Act as an open relay or a campaign sender.

Alias ceilings matter on day one of a team migration: three on Free, 15 on Solo, 50 on Starter, 200 on Business, 500 on Agency. Domains: one on Free and Solo, then 5 / 25 / 100. Seats: 1 / 1 / 5 / 25 / 50. If you need a hosted mailbox for every person, stop and buy Workspace instead.

Cost, alternatives, and trade-offs

Do not paste a remembered ImprovMX number into a board deck. Read ImprovMX — product documentation at decision time. MailerZ numbers below are plan limits, not an inbox-placement SLA.

Solo is the usual first paid step for one operator: $40 per year, 15 aliases, 90-day store, 5 send-as per hour, 100 outgoing per month. Starter fits a small Gmail team that needs five seats and 50 aliases. Annual Starter, Business, and Agency billing includes two months free relative to paying monthly for a year. Solo has no monthly option.

A hybrid that fails: ImprovMX MX still published “as backup” beside MailerZ. That is leftover MX with extra steps. Pick one receiving answer.

Another hybrid that fails: keep ImprovMX for inbound and bolt MailerZ SMTP on for send-as, or the reverse. Two vendors mean two logs when a customer says a message vanished. You will spend the afternoon arguing about which hop lied. If you need both directions, put both on one layer you can actually read. If you only need inbound, do not buy SMTP on a second brand to feel complete.

Cloudflare Email Routing is inbound routing for people who already treat Cloudflare as DNS. It does not become MailerZ leftover-MX handling, stored failed hops, or authenticated send-as because this article mentioned it. Fastmail, Workspace, and Microsoft 365 are mailbox hosts. They win when the store must move. They lose when the store is already Gmail and you only needed MX. Registrar “free email” is usually a tiny webmail box that later becomes leftover MX. Do not add it as a fourth hop “just in case.”

Agency at $39 monthly or $390 yearly exists for many domains and aliases, not for inbox-placement magic. If you manage client domains, count domains first: Free is one domain. Solo is three domains. Starter is five. Business is 25. Agency is 100. Recreating 40 client aliases on Free will fail the plan math before DNS has a chance to fail. Do the spreadsheet, then pick the card.

FAQ

Key takeaways

• An ImprovMX alternative for Gmail teams is an MX swap, not an inbox export.
• Recreate aliases before you publish the new MX.
• Leftover ImprovMX or Google MX is a hard stop.
• Header From stays the original sender. Envelope SRS is the allowed rewrite.
• Test inbound from a different mailbox. Self-send lies.
• Free has three aliases and no send-as. Count routes before you cut over.
• Paid SMTP is optional. Inbound proof is not.
• Compare ImprovMX on their current site. Do not quote remembered prices.
• MailerZ is not Workspace, not IMAP, not SOC 2, and not a bulk sender.

Conclusion and next action

If you came here for an ImprovMX alternative, keep Gmail. Recreate the routes. Publish one MX set. Prove inbound. Add paid send-as only if the From identity has to travel. That order prevents the two classic failures: a forgotten alias that used to work, and a verification email that landed on the old host.

MailerZ fits when you want that split with delivery history and a recovery window. It does not fit when you need a hosted mailbox for every user or campaign-scale sending. Start on Free if you only need to watch inbound on one domain. Move to Solo or another paid plan when alias count or send-as requires it.

Next action: add one domain, recreate one production alias, and send a uniquely titled message from a mailbox that is not the destination. Keep the old MX written down until that lands.

Review quarterly, or sooner if ImprovMX packaging, MailerZ plan limits, or DNS guidance changes. Author: MailerZ editorial, Secuno LLC.