Email Routing

Email Routing gives your domain real email addresses without renting a mailbox. Create info@example.ir, point it at an inbox you already use — Gmail, Outlook, your company mailbox — and nsin delivers everything sent to that address straight into it.

nsin publishes the DNS records, receives the mail, and hands each message on. Find it under Email in your domain's sidebar.

What it is, and isn't

Email Routing is a forwarder, not a mailbox.

• Nothing is stored. A message exists on nsin only for the seconds it takes to pass along — no inbox, no archive, no re-delivery later.
• Replies come from your own mailbox. Reply to a message that landed in your Gmail, and it goes out as your Gmail address, not info@.
• You can send a message as the address from the panel. The Send tab writes a plain-text message from info@example.ir to anyone — see Sending. There is no SMTP server to plug into Gmail or Outlook, though: to reply from your mailbox as info@, set up Gmail's Send mail as (or Outlook's equivalent) with an SMTP server from your host, Workspace account, or a transactional provider.
• Addresses live on the domain itself. info@example.ir works; info@mail.example.ir (a subdomain) doesn't yet.

Requirements

• Managed DNS. Email Routing writes MX, SPF and DKIM records into your zone, so the domain needs Managed DNS mode. Domains on external nameservers can't use it yet.
• Every plan includes it, including Free. Plans differ only in how many addresses a domain can have and how many messages it can forward per day — your numbers and usage are on the Email page. See Plans.
• Sending is a plan feature. Whether a domain can send, and how many messages a day, depends on its plan — the Send tab shows both.
• If Turn on email isn't showing, nsin's mail servers are briefly unavailable. Try again shortly.

Turning it on

1. Open your domain, go to Email.
2. Type the address you want (info) and the mailbox that should get its mail (you@gmail.com).
3. Press Turn on email. nsin writes the records below, locks them, and starts accepting mail. You don't copy anything; Show the DNS records we add is there if you want to read them.
4. Open the link nsin emails to that mailbox, within 24 hours. Mail is forwarded after that click. Anyone with access to the mailbox can click it, so a colleague can confirm their own address without an nsin account. No email? Use Send again at the top of the page (after 60 seconds) and check spam.

If the mailbox is your own nsin account email and that email is already verified, there is no link to click — mail flows straight away.

To add more addresses later, press New address and either pick a mailbox from the list or type a new one right there.

Mail usually flows within minutes — see DNS takes a moment below if it doesn't.

The records nsin adds

MX tells mail servers to deliver your domain's mail to nsin. SPF says nsin may send on your behalf. DKIM publishes the public half of a signing key unique to your domain, so your destination can verify a message really came through you.

The panel always shows the exact records for your domain (Show the DNS records we add before you turn it on, DNS details after).

Your existing mail records

Email Routing replaces your current mail setup. If your domain already has MX records (Workspace, Microsoft 365, your host, an old server), mail can't go to two places — nsin won't overwrite them quietly:

• Before enabling, the panel lists the MX records it would remove; you must tick a box to confirm.
• Removed records are kept as a snapshot. Disable Email Routing later and choose restore my previous MX records to get them back exactly.

An existing SPF record is merged, never duplicated. This:

v=spf1 include:_spf.google.com ~all

becomes:

v=spf1 include:_spf.google.com include:_spf.nsinmail.ir ~all

A domain may have exactly one SPF record — two is a permanent error that breaks all outgoing mail. If your zone already has more than one, enabling stops and asks you to merge them first.

Locked records

While on, those records are locked — visible, but not editable or deletable, so a stray edit can't silently kill your mail.

Unlock them when moving your mail elsewhere: routing keeps working as long as the records still point at nsin, so you can cut over at your own pace. Lock again if you change your mind, or use Disable to leave properly — it removes the records and can restore your old ones.

Sending

The Send tab sends a plain-text message from one of your domain's addresses to anyone.

1. Pick the address to send From — it has to be an address that exists on the domain and is switched on — and, if you like, the name shown next to it.
2. Add the recipients, a subject and the message.
3. Press Send. The message is queued and goes out a few seconds later.

The Sent list underneath shows one line per recipient: Queued, then Sent, or Failed with the receiving server's own words for why. A temporary problem is retried a few times by itself (Trying again).

Good to know:

• Replies come back to that address, so they are forwarded to your mailbox like any other mail.
• The message is signed with your domain's DKIM key and passes SPF and DMARC for your domain — the records Email Routing published already cover it.
• Plain text only — no HTML, no attachments.
• Your plan sets a daily limit, counted per recipient, and a message can go to a handful of recipients at once. Both numbers are on the tab.
• If many of a day's messages are refused by the receiving servers, sending from the domain pauses until the next day. This protects your domain's reputation, and everyone else's.
• nsin keeps who you wrote to, the subject and the result for 30 days. The text of the message is not kept.

This is for person-to-person mail — a reply to a customer, a quote, a follow-up. It is not a bulk or newsletter service.

Custom addresses

Each address has one action:

• Forward to — exactly one destination (no fan-out to several people yet).
• Drop — accept and silently discard. Useful for an address an old form still uses: the sender sees "delivered", you see nothing.

Details:

• Case doesn't matter — Info@ and info@ are the same address.
• A dot is a real character — first.last@ ≠ firstlast@ (Gmail ignores dots; your domain doesn't).
• Letters, digits, common punctuation, up to 64 characters before the @. Persian/Arabic characters aren't supported there.
• An unconfirmed address doesn't run — shown as waiting for the confirmation click until the destination confirms.
• Mail to an address you never created is refused with "user unknown", same as a real mailbox that doesn't exist. Turn on a catch-all to avoid refusing anything.

Catch-all

The catch-all handles mail for addresses you haven't created — hello@, billing@, a typo of your name. Turn it on and give it one action: forward everything, or drop everything.

Match order, first wins:

1. An exact address you created.
2. The subaddress rule, if on.
3. The catch-all.

Forwarding is convenient but noisy — spam dictionary attacks land in your inbox. Dropping is quiet, but a customer who mistypes sales@ as sale@ never learns why nothing happened.

Subaddressing (the + trick)

Off by default, per domain. On, info+newsletter@example.ir delivers to info@: nsin cuts at the first + and matches what's in front. It's how you hand a different address to every service you sign up for, and later see who sold yours on.

An address that literally contains a + wins over the stripped match: info+shop@ with its own destination goes there, while info+anything-else@ still lands on info@.

Destinations

A destination belongs to your account, not one domain. Confirm me@gmail.com once and point addresses on every domain at it — you'll never confirm it twice.

• The list on a domain's page belongs to the domain's owner. As an Editor on someone else's domain, you pick from their destinations. See Sharing a Domain.
• Resend works again 60 seconds after the last send; a confirmation link expires after 24 hours.
• Deleting a destination disables every address pointing at it, on every domain, immediately — the panel shows how many first. Addresses are kept; point them at another destination to revive them.
• A destination can't be an address on a domain itself routed through nsin — that's a loop, and is refused.

The activity log

The Activity tab shows every message nsin handled: when it arrived, who from, which address, the subject, and what happened. A summary above covers the last 30 minutes to 30 days.

Open a row for the checks nsin ran on the sender (SPF, DKIM, DMARC, ARC), the sending server's address and name, encryption in each direction, message size, and the exact reply from your destination's server — the one to read when a message says rejected or deferred.

Why a message might not arrive

Forwarding is stricter than a normal mailbox, because everything nsin passes on goes out under its own name. Mail is turned away when:

• The sender proved nothing — no SPF pass or valid DKIM signature. Almost always a contact form or script on cheap hosting set up wrong; the fix is on the sending side.
• The sender's domain says "reject" — a DMARC policy of p=reject that the message fails, usually from a signature broken by forwarding. nsin honours that policy rather than forward mail its owner disowned.
• Your destination refused it — full mailbox, spam filter. nsin relays their exact answer back to the sender.
• The daily forward limit was reached — a temporary error; mail near your ceiling usually arrives once it resets.
• The message was too big — over 25 MiB, including attachments.

Every case shows in the activity log with its reason.

Limits

One recipient at a time. A message to both info@ and sales@ delivers the first copy immediately; the sender's server retries the second a few minutes later. Both arrive.

nsin never generates bounce messages. Unknown addresses are refused while the sending server is still connected, so the sender always hears from their own provider — never a surprise message from an unknown domain.

What nsin does to keep your mail deliverable

Forwarded mail is the hardest kind to deliver: Gmail sees a message from someone else, arriving from a server that isn't theirs. Four things keep it in the inbox:

• Envelope rewriting (SRS) — the hidden return address is swapped for nsin's, so checks point at the server that really sent it. The From: line stays untouched, so replying still reaches the sender.
• A seal (ARC) — forwarding breaks the sender's original SPF check. The ARC seal is nsin's signed statement of what arrived and what passed, so your destination can reconstruct the truth.
• Double DKIM signing — once as nsin, once with your own domain's key, so forwarded mail carries your own reputation, not a shared one.
• TLS encryption in both directions whenever the other server offers it.

The message itself is never altered — nsin adds headers on top; subject, body, attachments and structure stay exactly as sent.

Troubleshooting

Nothing is arriving

1. Press "Check DNS" on the Email page — it checks your records publicly and shows exactly which is missing or wrong.
2. Give DNS a moment. Servers cache old MX records for a while after a switch; this resolves itself.
3. Check the address is on and its destination confirmed.
4. Look at the Activity tab. A row means the message reached nsin. No row means the sender never reached nsin — check DNS, or their provider.

Your test message vanished

Send the test from a different address than the destination. Testing from the same Gmail account you forward to makes Gmail hide its own message coming back — the forward worked, you just don't see it. The most common false alarm.

It arrives, but in spam

Mark it not spam once, and add a mailbox filter for that address. New setups take a little time to establish with the big providers.

Turning it off

Disable on the Email page removes those records and stops accepting mail. You'll be asked whether to restore your previous MX records — say yes if returning to your old provider.

Your addresses and destinations are kept, so re-enabling later isn't starting over.