> For the complete documentation index, see [llms.txt](https://docs.yeymail.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yeymail.com/using-yeymail/sending-and-replying.md).

# Sending and replying

There are two ways to send mail as an alias, and they solve different problems.

## Replying

**Hitting reply answers as your alias.** Every message we forward carries a YeyMail reply address, so when you press Reply your answer comes back through us and goes out as the alias. The person you are writing to sees the alias. Nothing to set up, and it does not matter which mail app you use.

This holds even when the message shows you the sender's real name and address, which we keep on every message so you can see who actually wrote to you. It also holds when a sender has tried to claim the reply for themselves by setting their own reply address, something marketing mail does routinely, because we replace it before the message reaches you.

**One thing to watch: Reply All.** Anyone else who was copied on the original message is still an ordinary address in your mail app. Replying to all sends to them directly, from your real address, alongside the anonymous copy that comes back through us. If other people were copied in, use Reply rather than Reply All, or send from the alias identity described below.

Starter includes **100 replies a day** through the automatic route; Plus is unlimited.

## Sending a new message as an alias

Replying only works on a conversation someone else started. To *begin* one (to email a shop from `shop@yourdomain.com` before they've ever written to you), give the alias its own SMTP password and add it to your mail app as a sending identity.

**Aliases → open the alias → Send as this alias (SMTP)**, and set a password there. Then follow the guide for your app:

| App                 | Guide                                                                               |
| ------------------- | ----------------------------------------------------------------------------------- |
| Gmail               | [Set up in Gmail](/using-yeymail/sending-and-replying/gmail.md)                     |
| Apple Mail on a Mac | [Set up in Apple Mail](/using-yeymail/sending-and-replying/apple-mail.md)           |
| iPhone or iPad      | [Set up on iPhone and iPad](/using-yeymail/sending-and-replying/iphone-and-ipad.md) |
| Thunderbird         | [Set up in Thunderbird](/using-yeymail/sending-and-replying/thunderbird.md)         |
| Outlook desktop app | [Set up in Outlook](/using-yeymail/sending-and-replying/outlook.md)                 |
| Anything else       | [Other mail apps](/using-yeymail/sending-and-replying/other-mail-apps.md)           |

Mail sent this way carries nothing that identifies your connection: your IP address, your provider and your mail client are all removed before the message leaves us.

## The settings

Every guide uses the same values. If your app isn't listed, these are all you need:

| Setting           | Value                                                         |
| ----------------- | ------------------------------------------------------------- |
| Server / hostname | `mx1.yeymail.com`                                             |
| Port              | `587`                                                         |
| Encryption        | **STARTTLS** (some apps call it "TLS" or "STARTTLS/explicit") |
| Authentication    | Normal password                                               |
| Username          | the full alias, e.g. `shop@yourdomain.com`                    |
| Password          | the SMTP password you set on that alias                       |

### Three things that catch people out

**Use port 587, not 465.** We don't run SSL-on-connect on 465. Apps that default to it will sit there and eventually time out, which looks like a broken password but isn't.

**Send from the same alias you signed in as.** The server checks that the From address matches the alias that authenticated. If they differ the message is rejected. You can't sign in as one alias and send as another. Each alias needs its own password and its own identity in your app.

**Your password is per-alias, not your account password.** It's the one you set in the dashboard for that specific alias. Your YeyMail login won't work here.

## Turning it off

Remove the SMTP password from the same panel in the dashboard. The alias keeps forwarding mail to you; it just stops being able to send. Worth doing for any alias you no longer send from, and immediately if a device is lost.

## Size limit

Messages up to **25 MB** send and forward normally, attachments included.

That is deliberately the same ceiling Gmail, Outlook and iCloud enforce, so a message YeyMail accepts is one your inbox will accept too. A higher limit would only mean accepting mail we then could not deliver.

Anything larger is refused while the sending server is still connected, so the sender is told by their own provider straight away rather than assuming it arrived. For bigger files, share a link instead.

## When a forward can't be delivered

If your real inbox refuses a forwarded message (a full mailbox, a provider rejecting it, an address that no longer exists), the person who wrote to your alias gets a short notice saying their message did not arrive.

**That notice names your alias and nothing else.** It does not name the inbox behind it, quote the failure your provider gave, or reveal that the alias forwards anywhere at all. A standard mail server answers a failed forward with a report reading *"<your-real-inbox@example.com> (expanded from <your-alias@yeymail.com>)"*: one sentence containing exactly the link an alias exists to break. YeyMail keeps those reports instead of passing them on.

The failure is recorded against your account, so you can see it in your delivery log. One hard bounce is enough: if an address answers with "no such user", YeyMail stops sending to it from that moment until you confirm it works again.


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