Apple Mail — mailbench

Results

Each column is one run. The place is among the clients in that run, lowest first; within one display frame of the fastest counts as a tie. Runs are not comparable with each other.

Test	250,000 messagesMac Studio, October 15, 2026version 16.0	50,000 messagesMac Studio, October 14, 2026version 16.0
Open a message	154 ms4 of 6	73 ms3 of 6
Next message	180 ms2 of 6	77 ms2 of 6
Search	254 ms2 of 6	120 ms2 of 6
Launch	724 ms3 of 6	1,691 ms4 of 6
Quit	116 ms4 of 6	218 ms6 of 6
Scroll	343 ms2 of 6	306 mstied for best
Memory	344 MB4 of 6	260 MB4 of 6
Idle CPU	24.3%5 of 6	1.7%3 of 6

Store on disk. Excludes the Envelope Index (~/Library/Mail/V*/MailData), which Mail shares across every account and cannot be attributed to this one.

Search. Apple Mail searches through Spotlight. The time is what a person waits for, not a comparison of search engines.

Setting it up

Install

Ships with macOS.

Add the benchmark account

Server 127.0.0.1, port 10143 (10144 for the 250k mailbox), no encryption, user bench@example.com, password bench.

Run ./mailbench account applemail, which adds the account through Mail's own scripting interface. It asks once for permission to control Mail.
Or by hand: Mail ▸ Add Account ▸ Other Mail Account. It will fail to guess the settings; on the manual sheet set the IMAP host and port and turn TLS off.
Let it sync on its own. Mailbox ▸ Rebuild is not wanted.

So it holds the whole mailbox

Apple Mail downloads every message in full by default. Nothing to change.

For a first-sync measurement

Delete the Bench account (Mail ▸ Settings ▸ Accounts ▸ −), then quit Mail.
Press Enter here, then add the account again with ./mailbench account applemail in another terminal.

Its window

80pt two-line rows, list between x 200 and 600, reader to the right, search in the toolbar.