1709560 - Explore not showing *inline* autocomplete suggestions when a full new email address *@* is entered (prevent error-prone, unwanted autocompletion)

Status: NEW

(Thunderbird :: Address Book, enhancement)

Description

[Thomas D. (:thomas8)]

Users have every right to expect that entering a full valid address and pressing Enter after that should result in that address and not some unrelated best match from recipient autocomplete. We're currently forcing users into deleting the unwanted completion, which is not exactly obvious, hence error-prone. Maybe we can be less aggressive about autocompletion in that particular case and make it opt-in rather than opt-out.

(Coming from Bug 1709322, comment 2, which is neither the first nor the only complaint.)

STR

1. compose
2. have this contact in your address book:
   John Doe <[e-mail]>
3. type new recipients which happen to be a substring of an existing address and press Enter:
   [e-mail] (sic, TLD co: same localpart, domain = substring of known contact's domain)
   [e-mail] (same domain, localpart = substring of known contact's localpart)

Actual result:

• Both addresses typed, in spite of being complete, valid, and new (not yet in your AB), will unexpectedly be autocompleted to your longer existing address, [e-mail], due to the accidental fact that they are a substring of that.
• It's not very obvious, hence error-prone that entering a valid address would require deleting an unwanted inline autocomplete proposal (Enter on selected text will typically overwrite/wipe out the text, not confirm it. Otoh, TB users might be used to this anomaly because that's how our autocompletion has worked ever since).
• For big companies which might have 100 different John Doe's in their address books, these are not exactly edge cases if you substitute example.com with a popular domain like gmail.com (especially for the 2nd case).

Expected result

I propose to explore the feasibility of the following:

• Pressing Enter after full, valid, new email address (unknown to address book) should result in that new address.
• I.e. when autocomplete search string is a single-word string that looks like a valid full email address (pattern: *@*), and the address is not known, Thunderbird should refrain from inline-autocompletion and only show the dropdown list with proposals to choose from.