Sending myself an email.

PBR American Apparel selvage, banjo actually next level chia gentrify cronut authentic. Shabby chic ennui health goth Banksy Intelligentsia PBR. Wolf irony health goth pug lumbersexual High Life cliche, heirloom Neutra. Narwhal slow-carb retro, organic Brooklyn typewriter Portland. Quinoa kogi literally, cardigan paleo viral vinyl occupy photo booth sartorial Brooklyn semiotics Shoreditch wayfarers drinking vinegar. Pour-over VHS flexitarian paleo pickled. Messenger bag Blue Bottle Kickstarter narwhal, gluten-free kogi banh mi Bushwick Godard fanny pack quinoa synth skateboard occupy chambray.

Modulo that terminal quote, I conclude this is a problem with your client.

I am just sending this email in an attempt to reproduce this behavior.
Hopefully it reproduces on this install.

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Hmm, interesting. I sent this from the Gmail app for Android.

This seems relevant: https://mathiasbynens.be/notes/gmail-plain-text

Testing from Gmail web client.

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est laborum. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed
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ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
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est laborum.

Would this be possible for #prioritization? I would work on it myself, but don't have any ideas for an appropriate fix.

I'm not sure there's anything we can really do about this. Gmail is applying a destructive transformation to outbound mail, and there is no inverse function we can apply to restore the original mail.

Specifically, there exist numerous cases where two different inputs to Gmail produce the same output, so we have lost information through the transformation and can not possibly restore the original message unambiguously in the general case.

We could try to detect the mail came from Gmail (or maybe more generally that it was not encoded with a linebreak-preserving encoding) and "unwrap" it, but we'll get this wrong some of the time. I would particularly expect us to get it significantly wrong for things like code blocks, although maybe the wrapped behavior is so bad already that this would still be an improvement and/or users only ever use mail to send human-readable messages.

There is also some discussion elsewhere of restyling comments to have a narrower width, which might work around this. A "creative" solution in this vein would be to render comments from email with a wrapped line-width in some sort of alternate UI that made them look nicer, although this doesn't feel like a great use of time to me.

Why is this behavior OK for all other email and not OK for email to Phabricator? Or is the mail you're sending really multi-part and you presume all other clients render the HTML version rather than the plain text version?