Writing mail

Nixt Mail has two places to write: the compose window, for new messages and for replies and forwards you want room for, and the reply box under an open message, for a quick answer to the sender.

Start a new message

Any of these opens the compose window:

• The Compose button at the top of the sidebar.
• C when you are not typing, or ⌘N (Ctrl+N on Windows and Linux) at any time.
• File › New Message.
• Compose new message in the command palette.
• On a narrow window, the compose button at the top of the list (tooltip Compose).

The window, titled New message, opens at the bottom right of the window. On a narrow window it fills the screen. If the AI panel is open, the compose window moves aside so both fit.

If you closed a message you had not sent, the compose window reopens with it. See Drafts.

The compose window

Messages are written as plain text.

Which account sends

• A reply or forward always goes from the account the original message arrived at, even when you are in All inboxes or another account is selected.
• A new message goes from the account selected in the sidebar, unless you choose an account in Settings › Composing › Send new mail from. That setting appears once you have two or more accounts; its choices are The selected account (default) and each of your addresses.

To send a new message from a different account, switch accounts in the sidebar first, or set Send new mail from.

Send from another address

When you have more than one account, or an account has other send-from addresses (see Send-from addresses), the From line has a small arrow. Click it and choose who the message goes out as: each account’s own address, and its other addresses under it. The chosen one is ticked.

A reply to mail that was sent to one of an account’s other addresses starts from that address — in the compose window, and in the reply box under a message. Reply all never copies you, at any of your addresses.

Recipients

Type addresses in To, Cc and Bcc:

• Separate several addresses with commas or semicolons.
• Type the address on its own, such as alex@example.com, or a name and address, such as Alex Morgan <alex@example.com>.

Show Cc and Bcc

Cc and Bcc are hidden until you choose Cc Bcc at the end of the To line. They show automatically when a message already has someone in them, so no recipient is ever hidden.

To have them on screen in every new message, set Settings › Composing › Show Cc and Bcc to Always shown. The default is When I ask for them.

Address suggestions

As you type in To, Cc or Bcc, Nixt Mail lists people you have exchanged mail with, most written-to first. A person who is waiting for a reply from you is marked owes a reply. People already in one of the other fields are not suggested again.

Until you move onto a suggestion, Return and Tab do what they normally do.

To stop suggestions — when you share your screen on a call, for example — turn off Settings › Composing › Address suggestions. What you type is kept and sent exactly as typed.

Reply, reply all and forward

Each opens the compose window, filled in:

• Reply addresses the sender — or the address the sender asked replies to go to, if the message set one. Your own addresses are never added.

• Reply all puts the sender and everyone in the original To in To, and everyone in the original Cc in Cc. None of your own addresses, from any of your accounts, are included.

• Forward leaves To empty and puts the original under a heading, with its sender, date, subject and recipients:

  ---------- Forwarded message ----------
  From: Alex Morgan <alex@example.com>
  Date: …
  Subject: Quarterly numbers
  To: Sam Lee <sam@example.com>

• A forward also carries the original’s attachments. They join the message’s attachments as they arrive from the server, and you can remove any before sending. If one cannot be fetched, Nixt Mail names it and the forward goes without it. To forward the text alone, set Settings › Composing › Attachments when forwarding to Leave them out.

• The subject gains Re: or Fwd:, unless it already has that prefix.

• A reply is threaded with the original, so other mail apps show it in the same conversation, and the original is marked as answered on the server.

If the compose window already holds a message you have not sent, Nixt Mail asks Replace your unsent draft? — Compose already has a message in it. Starting this reply will discard what is there. Choose Keep draft to keep writing it, or Discard and reply (or Discard and forward) to start the new one.

Which reply button comes first

Settings › Composing › Default reply chooses Reply (default) or Reply all for the first reply button in the reading pane’s toolbar. The other is always the button beside it. With Reply all first, the second button’s tooltip reads Reply to sender only.

The reply box

Under an open message is a box for a quick reply. Until you use it, it is one line: Reply to and the sender, over Write your reply…. Click it, or move to it with Tab, and it opens with Send reply and the controls below; once open, it stays open for that message.

1. Click in the box and type your reply.
2. Choose Send reply, or press ⌘Return (Ctrl+Return on Windows and Linux).

The reply goes to the sender only, from the account the message arrived at. The line beside the button says To: and the sender’s name. A snack bar confirms Reply sent to and the address — or, with undo sending on, the undo bar appears.

On a narrow pane, the buttons shorten to Draft and Send, and Quote, Templates and the To: line are hidden.

A quoted reply looks like this:

Thanks, that works for me.

On 12 Sep 2026 at 14:05, Alex Morgan <alex@example.com> wrote:
> Can we move the review to Thursday?

Each quoted line starts with >. Very long messages are quoted up to 250 lines, followed by > [earlier messages trimmed].

What you type in the reply box is kept for each message while Nixt Mail is open, so moving to another message and back does not lose it.

To give the message the whole reading pane, turn off Settings › Composing › Quick reply box. Replies then open in the compose window. A reply you had half-written is kept and reappears when you turn the box back on.

Spelling

On a Mac, Nixt Mail checks spelling as you type in the message, the subject and the reply box, with your Mac’s dictionaries and spelling languages. A misspelled word gets a dotted red underline.

Right-click an underlined word to:

• choose a correction, which replaces the word;
• choose Learn Spelling, which adds the word to your Mac’s dictionary, so no app flags it again;
• choose Ignore Spelling, which stops flagging it until Nixt Mail quits.

Addresses in To, Cc and Bcc are not checked. To stop checking, turn off Settings › Composing › Check spelling as you type.

Attachments

1. In the compose window, choose the paperclip (tooltip Attach files).
2. Pick one or more files.

Each file appears under the message with its name and size. Choose × on a file (tooltip Remove and the file name) to take it off.

• Files larger than 100 MB are refused as you add them: the file name followed by is too large to attach and its size.
• Files that are not stored on this computer, such as some cloud-drive selections, are refused: the file name followed by is not a local file, so it cannot be attached.
• When AI is set up, a sparkle on a file lets you ask about it before you send. See AI features.

To send files, use the compose window. Sending edited documents back to their sender is covered on Attachments and documents.

Templates

A template is text you keep to put into messages: an answer you give often, directions, a confirmation. Templates are plain text, like everything you write in Nixt Mail.

Put one in

1. In the compose window or the reply box, click the page icon, Templates.
2. Choose a template by its name.

Its words go where the cursor is, replacing anything selected. If you have not clicked into the message yet, they go at the top, above the quoted message. If the template has a subject and the message’s subject is empty, the subject is filled in too; a subject you already typed is never replaced.

Keep what you wrote as a template

1. Write the message.
2. Click Templates and choose Save as template…. It is greyed out while there is nothing written.
3. Name the template. The name starts as the message’s subject.
4. Click Save.

What you wrote is kept without the quoted message or your signature. From the compose window, the subject is kept with it.

Manage templates

Choose Templates › Manage templates…, or open Settings › Composing › Templates.

Templates are kept on this device. Restore defaults leaves them alone.

Signatures

A signature is the few lines added to the bottom of the mail you send. Each account has its own.

Write a signature

1. Open Settings › Signatures.
2. Under Each account, if you have several accounts, choose the account’s address.
3. Type the signature in the box. It is saved as you type.

The signature is added when the message is sent, so you do not see it in the compose window or the reply box.

A shorter signature for replies

A full signature — a title, a phone number, an address — is repeated at the bottom of every message in a long conversation. You can give each account a shorter one for replies and forwards, such as just your name.

1. Open Settings › Signatures.
2. Under Each account, choose the account’s address if you have several. The Signature for replies box below follows the account chosen above it.
3. Type the shorter signature in Signature for replies. It is saved as you type.

Replies and forwards from that account then end with the shorter signature, and new messages with the full one. While the box is empty it shows the full signature in grey, and replies and forwards use the full signature. With Use the signature in set to New mail only, replies and forwards have no signature, and the box is replaced by a line saying so.

Signature settings

Checks before sending

When you send from the compose window, Nixt Mail can ask up to four questions first. Each is a dialog with Don’t send, which leaves the message open as it was, and Send anyway.

Sending

Choose Send, or press ⌘Return (Ctrl+Return on Windows and Linux).

Before anything else, Nixt Mail checks the recipients:

• An address it cannot read stops the send with, for example, “alex@example” is not an email address.
• A message with nobody in To says Add someone to send this to.

A message with an empty subject is sent as (no subject).

Send with the keyboard, or not

Settings › Keyboard › ⌘Return sends is on by default: ⌘Return and Ctrl+Return send from the compose window, and from the reply box once you have written something, asking every question Send asks. Turn it off so that only the Send button sends.

Send later

1. Write the message.
2. Click the clock beside Send, Send later.
3. Choose Tomorrow morning (8:00), Tomorrow afternoon (13:00), Next work week (8:00 on the first day after your weekend; not offered when that is tomorrow), or Pick a date and time…. Each shows the time it means.

Before it is scheduled, the message is checked as Send checks it: an address that is not one, no recipient, and every question under Settings › Composing › Before sending, ask about. The window then closes, and a snack bar says Scheduled to recipient, and when, with Undo to put it back in the compose window.

When your mail server can hold it. Some servers — Nixt Server, Fastmail and other JMAP servers that offer it — will hold a message and send it at a set time. For an account on one of them, Nixt Mail hands the message to the server as soon as it is scheduled, and the server sends it at its time whether Nixt Mail is open or not, and whether your computer is on or not.

Otherwise, Nixt Mail sends it. For other accounts, Nixt Mail sends the message at its time while it is open. If Nixt Mail is closed then, it sends it as soon as you next open it, and says Sent 1 scheduled message. If its account is not connected yet, it waits until it is. Until then the message is kept on this computer, encrypted with the same keychain key as offline mail, and nowhere else. It is gone once sent, or put back as a draft.

A scheduled reply is threaded with the message it answers. After sending a reply does not archive the conversation when a scheduled reply goes.

The Scheduled list

While anything is waiting, Scheduled, with a count, appears in the sidebar under Awaiting reply. Click it to see each message: its subject, who it is to, and when it sends — from its server, with Nixt Mail open or not, or if Nixt Mail is open, or when it next opens — or, in red, why it could not be sent at its time. One that could not be sent is not tried again on its own: press Send now when the problem is fixed, or put it back as a draft.

Undo sending

With undo sending on, a sent message waits before it goes to your provider. While it waits, a bar at the bottom of the window says Sending to and the recipients, with:

• Undo — takes the message back and reopens it exactly as it was, including its attachments. If the wait has already run out, a snack bar says Too late — that one has already gone.
• Send now — sends it straight away.

Settings › Composing › Time to undo sending chooses Off, 5 seconds (default), 10 seconds or 30 seconds. The wait applies to new messages and to replies from the reply box alike. With Off, mail goes to your provider the moment you send, and a snack bar says Sent to and the recipients.

Only one message waits at a time: sending another sends the first immediately. If you quit Nixt Mail while a message is waiting, it is sent.

Bcc myself

Turn on Settings › Composing › Bcc myself to put your own address in Bcc on everything you send, so a copy lands in your inbox. It is added only to what is sent, and not if you are already a recipient. If you undo a send, the Bcc field comes back as you typed it. Off by default.

Archive after replying

Settings › Composing › After sending a reply chooses Leave it where it is (default) or Archive the conversation. With Archive the conversation, the conversation you replied to is archived once the reply has actually gone — after the undo wait — so undoing a reply leaves it where it was. It applies to replies from the compose window and from the reply box.

Text size while writing

Settings › Appearance › Text size when writing makes what you type Smaller, Standard (default), Larger or Largest.

Drafts and closing an unsent message

Close and keep

Choose × at the top of the compose window, or press Esc. The window closes and keeps what you wrote:

• Nixt Mail holds the message and reopens it the next time you open the compose window.
• For a connected account, it also saves a copy to the account’s Drafts folder on the server, so you can find it in any mail app. A snack bar says Saved to Drafts.
• An empty message is not saved, and closing again without changes does not save another copy.

Ask before closing

Set Settings › Composing › Closing an unsent draft to Ask first to be asked whenever you close a message with anything in it — by × or by Esc. The dialog Keep this message? says It has not been sent. Keep it as a draft to finish later, or discard it., with:

• Keep writing — returns you to the message.
• Discard — throws it away.
• Keep as draft — closes and keeps it, as above.

The default is Keep it as a draft, which closes without asking.

If Nixt Mail closes while you write

A crash, a forced restart or a flat battery does not lose the message you are writing. Settings › Composing › Keeping a message safe while you write decides how:

Discard

Choose the trash button (tooltip Discard). If the message has anything in it, Discard this message? asks first — What you have written will be deleted. This can’t be undone. — with Keep writing and Discard.

Error messages

When a server refuses a message, the server’s own explanation follows the sentence, after It said:.

What Nixt Mail never does

• It never sends without you. Rules cannot reply or forward, AI cannot send, and an unsubscribe by email only starts a message for you to send.
• It never reveals Bcc recipients. People in Bcc receive the message, and nobody else on it can see them.