Skip to main content
A subdomain gives you your own slice of a Maski-owned domain — for example mycompany.alias4me.in — and every address beneath it is yours. Unlike a custom domain, there is nothing to configure: no DNS records, no verification, no waiting. You claim the name and it starts receiving mail within a second.
Subdomains are a Pro feature. Pro includes 5 subdomains. They are counted separately from custom domains, so having one does not use up the other.

​
Subdomain or custom domain?

Both give you a namespace you control. They differ in what they cost you to run. Pick a subdomain when you want a tidy, branded-ish namespace today without buying or configuring anything. Pick a custom domain when the address needs to be on a domain you own — for a business, or to start new conversations as well as receive and reply.

​
Claiming one

Go to Subdomains in the dashboard and choose a label. The label is the part you pick; the rest is the Maski domain it sits under, chosen from a list. Today that list holds one domain, alias4me.in. Labels are checked as you type. Some are unavailable:
  • Anything already claimed, by you or anyone else.
  • Infrastructure names — mx, mail, smtp, www, bounces, and similar.
  • Brand and role names, for the same reason Maski restricts them on shared addresses: paypal.alias4me.in would be a convincing thing to pretend with.
  • Punycode (xn--) labels, and anything outside letters, digits and hyphens.
The check tells you the truth about a name without holding it. Two people typing the same label are both told it is free, and whoever presses Claim first gets it.

​
Choosing what arrives

A subdomain has an inbound mode, which decides what happens to mail for an address you have not explicitly created. You pick one when you claim, and you can change it at any time — a change takes effect on the next message, with nothing in flight to migrate.
Mail to any other address on the subdomain is discarded, and the sender is not told. The tidiest option, and the default.
A single * address receives all mail for the subdomain, wherever it was sent, and forwards it to one destination.
The * address acts as a template. The first time mail arrives for a new address, Maski creates a real alias from that template. From then on the address has its own settings, its own counters, and its own pause and sender rules — you can manage it like any other alias.

​
The * address

Catch-all and auto-create both deliver through a * address. A subdomain in one of those modes with no * address yet delivers nothing, and, as with manual mode, the senders are not told. Maski never guesses a destination on your behalf, and it never leaves you in that state without saying so:
  • When you claim into catch-all or auto-create, the dialog offers to create the * address for you, ticked by default, and names the destination it will forward to. Untick it if you would rather set it up yourself.
  • On the subdomain’s page, if a delivering mode has no * address, the page says so and gives you Add catch-all — one click, no dialog.
  • Add address on the same page creates a named address like work@mycompany.alias4me.in, with the subdomain already selected.
The destination is your account’s default destination, falling back to your login address. That matters most under auto-create, where the * address is the template every auto-created address inherits its destination from.
A * address you create counts as one of your plan’s aliases, the same as a catch-all on a custom domain. At most one per subdomain, so a Pro account that gives all 5 subdomains a catch-all spends 5 of its 25 aliases. If you are already at the alias limit when you claim, the offer stands down and says so — the claim still goes through, and you can add the * address after freeing a slot.

​
Addresses created by inbound mail

Under auto-create, addresses appear because someone mailed them, not because you made them. On the subdomain’s page they are marked Created by inbound mail so you can tell them apart from the ones you made. They do not count against your plan’s alias limit — you did not create them, and a stranger mailing a hundred random addresses at your subdomain should not be able to stop you making aliases by hand. They are limited separately, per subdomain: up to 200 auto-created addresses each, and a cap on how many new ones can appear in an hour so a burst cannot fill your list. Reaching either limit never costs you mail. New addresses keep forwarding through the * template, exactly as a plain catch-all would; you just stop getting a separate row per address.

​
Addresses beneath your subdomain

Every address under a subdomain you hold is yours alone, so the shared-domain restrictions do not apply. support@, hello@, careers@ and billing@ are all available to you, and short names of two characters are allowed.

​
Replies and sending

You can reply to anything Maski forwards you from a subdomain address. Reply as normal from your own mail client and Maski routes the message back out as the subdomain address, so the other person never sees your real inbox. Setting a sender name on the alias works here too. You cannot start a new conversation from a subdomain address — send-from-alias needs a verified custom domain. Mail from your subdomain is signed under the shared Maski domain, so allowing fresh outbound would let one account’s behaviour affect delivery for everyone else on that domain. A subdomain is reply-only, the same as a shared Maski address.

​
If your Pro plan ends

Subdomains are disabled, not released, when an account goes back to free. The names stay yours and keep their addresses; mail stops arriving until you upgrade again, at which point they come back as they were. Nothing is burned and nothing is handed to anyone else. While a subdomain is disabled you cannot add addresses to it — an address on a name that routes no mail would be a dead end — and the page says so rather than offering a button that does nothing.

​
Releasing a subdomain

Releasing frees the slot against your plan limit. It does not free the name.
A released subdomain is burned permanently. Nobody can claim it afterwards — including you.This is deliberate. People and services go on mailing a name long after you stop using it. If the name could be re-issued, whoever claimed it next would receive your password resets, your bank mail and your two-factor codes, for every address beneath it at once. The addresses you created are retired rather than deleted.
You confirm a release by typing the subdomain’s label. If you only want to stop paying, downgrading is the reversible option — see above.

​
About DMARC checkers

If you run an external DMARC checker against your subdomain, some will report “no DMARC record” or “invalid DMARC record”. This is a reporting artifact, not a fault, and your mail is unaffected. The reason is a detail of how DNS wildcards work. Maski publishes one wildcard record that covers every subdomain, and that wildcard also answers at the name where a checker looks for a DMARC policy. Receivers follow the spec here: they ignore anything that is not a DMARC policy and fall back to the policy on the parent domain, which is published and correct. Strict checkers stop at the first answer and report it as broken. Mail from your subdomain is signed and aligned on both SPF and DKIM, and passes DMARC. If you want to confirm it yourself, check the policy on the parent domain rather than on your subdomain, or send a message to a mailbox that shows authentication results.

​
Limits

  • Pro includes 5 subdomains. Free includes none.
  • A * address you create counts as one of your plan’s aliases. Addresses created by inbound mail do not.
  • Auto-created addresses are capped at 200 per subdomain and rate-limited. Reaching a limit degrades to forwarding through the * address; mail is never dropped for it.
  • Starting a new message from a subdomain address is not supported. Replies are. Use a custom domain if you need to send first.
  • Brand logos (BIMI) are not available on a subdomain. Publishing the record a logo needs would stop the wildcard answering for your name, and your mail would stop with it.