---
title: Sending mail
updated: 2026-10-15
summary: Who you can email, from which address, signatures and automatic replies.
section: Your inbox
order: 2
---

## Choosing an address

Send from your real address or any active alias. Replies go out from the address the email came to. You can't send from a blocked alias.

Sending from your real address approves the people you write to, so their replies skip [Screening](/help/screening). Sending from an alias doesn't.

## Forwarding

Forward any email from the conversation, with its attachments. Open the message and choose **Forward**, or press **f**. Yellowbird makes a draft from the alias the email came to, so a company only ever sees the address it already has. You can change the sender and add recipients before you send.

On a free plan you can only forward to people who've emailed you first, the same as any other email you send.

## Signatures

Set a signature for your real address in **Settings → Sending**. Each alias has its own, on the alias's page. Aliases have none unless you add one, since a signature can give away your name to a company that only has the alias.

The signature is added when you start an email or a reply. If you change the address you're sending from, it switches to that address's signature, unless you've edited it.

## Automatic replies

Going away? Turn on an automatic reply in **Settings → Sending**, and optionally set your last day away. It turns itself off after that day.

It only answers mail to your real address from people who reach your inbox. It never goes to new senders in Screening, mailing lists, or other automatic mail. Aliases never send one, so companies can't tell an alias is in use. Each person gets it at most once every 4 days.

Automatic replies are saved in **Sent**, and count towards the people you can email each day.

## Who you can email

On a free plan you can email people who've emailed you first, up to 10 people a day. The count resets at midnight UTC. Paid plans can email anyone.

## Limits on every email

- Up to 50 recipients
- Up to 20 attachments, 3.5 MB in total

Emails are plain text.

## Large files

On a paid plan, files over 3 MB, or files that would take the attachments past 3.5 MB, are sent as links instead. Each can be up to 50 MB. Anyone with the link can download the file until you delete the email from Sent, so only send links to people you trust with the file. Linked files count toward your storage.

## Images in mail you receive

Pictures from the web are blocked until you choose **Load images**, because they can tell the sender when you opened their email. Yellowbird shows how many trackers it held back, and who they're from.