aerc vs nmail

aerc: Terminal email client written in Go with IMAP, JMAP, Maildir and notmuch backends and an embedded terminal for editing.
nmail: Terminal email client for Linux and macOS with an Alpine-like interface and built-in IMAP and SMTP.

Differences

Only aerc has built-in JMAP, Maildir, mbox and notmuch.
On Windows, aerc runs through WSL and nmail is not available.
On BSD, aerc runs natively and nmail is not available.
On Android, aerc runs through Termux and nmail is not available.
aerc has mouse support; nmail does not.
aerc has calendar support; nmail does not.
aerc has OpenPGP; nmail does not.
aerc has Vim-style keys; nmail does not.
aerc has multiple accounts; nmail does not.
aerc has threaded views; nmail does not.
aerc is written in Go; nmail in C++.
Configuration: aerc uses INI-style files: accounts.conf, aerc.conf, binds.conf, and nmail uses ~/.config/nmail/main.conf key=value file.

Side by side

	aerc	nmail
Interface	Full-screen terminal interface	Full-screen terminal interface
Language	Go	C++
License	MIT	MIT
Latest version	`0.22.0`	`v5.16.4`
Linux	Native	Native
macOS	Native	Native
Windows	Through WSL	No
BSD	Native	No
Android	Through Termux	No
IMAP	Yes	Yes
POP3	No	No
SMTP	Yes	Yes
JMAP	Yes	No
Maildir	Yes	No
mbox	Yes	No
notmuch	Yes	No
OpenPGP	Yes	No
S/MIME	No	No
OAuth2 sign-in	Yes	Yes
Threads	Yes	No
Search	built-in; server-side for IMAP and JMAP; notmuch queries	local cache index and server search
HTML mail	via filters, w3m by default	converted to text, or opened in an external browser
Mouse	Yes	No
Multiple accounts	Yes	No
Offline use	with mbsync or OfflineIMAP through the Maildir backend; IMAP header cache	local SQLite cache; offline mode and send queue
Calendar	Yes	No
Contacts	via address-book-cmd, e.g. khard or the bundled carddav-query	address book built from messages
Vim-style keys	Yes	No
Configuration	INI-style files: accounts.conf, aerc.conf, binds.conf	~/.config/nmail/main.conf key=value file

Which to choose

Choose aerc for

Embedded terminal runs the editor and other commands inside aerc
Built-in commands for applying and reviewing git patch series
Supports JMAP and notmuch as well as IMAP and Maildir

Watch out for

No POP3 or S/MIME support
mbox files open read-only
No native Windows build

Install aerc

Choose nmail for

Built-in IMAP and SMTP with setup wizards for Gmail, iCloud and Outlook
Local cache, address book and outgoing queue can be encrypted
Compose HTML mail using Markdown

Watch out for

One account per running instance
No threaded view and no PGP or S/MIME
Linux and macOS only; no Debian or Fedora package

Install nmail

Questions

What is the difference between aerc and nmail?

Only aerc has built-in JMAP, Maildir, mbox and notmuch. On Windows, aerc runs through WSL and nmail is not available. On BSD, aerc runs natively and nmail is not available.

Which runs on Windows, aerc or nmail?

On Windows, aerc runs through WSL. On Windows, nmail is not available.