Bug report: Some marketing emails render at an extremely narrow width

[GodfreyJH]

Bug report: Some marketing emails render at an extremely narrow width

Hi Kim,

Thank you for your continued work on Tachyon.

I've encountered a problem displaying certain marketing emails. The email content is squeezed into a very narrow column in Tachyon, making the messages difficult to read.

I've tested the same original emails in both Thunderbird and Outlook, where they display correctly at a readable size. The problem appears to be specific to how Tachyon renders these messages.

I've encountered this with at least two marketing emails advertising Acer products. Other marketing emails I've received, including messages from other suppliers, display correctly in Tachyon.

I appreciate that marketing emails can contain complicated or imperfect HTML, so I haven't established the exact cause. However, the difference in rendering between the clients suggests there may be an issue worth investigating.

If helpful, I can provide the original .eml files for testing, along with any further information you need.

Thank you again for your work on Tachyon.

[kimusan]

Thanks, and sorry for the trouble. I had a look and found at least one way a message can end up like this, though I cannot say yet whether it is what is hitting your Acer mails.

Tachyon rewrites fixed pixel widths in a message into percentages, so a 640px newsletter fits the reading pane instead of needing a horizontal scrollbar. A percentage resolves against the parent element, and the wrapper many senders put around a mail is a table with no width of its own, which shrinks to fit its content. In the test messages I built, that made the percentage resolve against the width of the longest word, and the mail came out as a narrow column. Blocked remote images did not change it either way.

Whether a mail is affected seems to depend on how the template was built, which would explain why most of yours are fine and these two are not. A wrapper carrying width="100%", or cells with their own widths, held up fine in my tests.

I have a change queued for the next release that gives such a wrapper a width for the percentage to resolve against. It fixed the two shapes I could break and left the others alone, but that is synthetic mail, not yours, so treat it as a candidate rather than a confirmed fix.

If you can still send the .eml files, that would help a lot. There is more than one way for a message to end up narrow, and I would rather check yours against the change than assume I have found the right cause. If it turns out to be something else, the files are the quickest route to it.

[GodfreyJH]

Hi Kim,

Thank you for investigating this so thoroughly.

I'd be happy to provide the original .eml files for testing. However, they contain email addresses, server IP addresses and other header information, so I'm not comfortable posting them publicly on GitHub.

Would you be happy to contact me at__________. I can then send the original files to you privately.

I'd prefer to keep the original messages intact so that you can test the actual emails rather than risk removing something relevant when sanitising them.

Thank you again for looking into this. I appreciate your willingness to investigate the problem rather than assume the proposed fix is necessarily the answer.

Best regards,

Godfrey