Tuta wrongly claims that certain valid e-mail addresses are invalid

[realpixelcode]

• This is not a feature request (existing functionality does not work, not missing functionality).
  I will request features on forum or via support.
• I've searched and did not find a similar issue.

Describe the bug

When entering certain recipient e-mail addresses that are valid according to RFC 5322, Tuta wrongly complains that they're allegedly invalid.

To Reproduce

Steps to reproduce the behavior:

1. Draft a new e-mail.
2. Enter any of the examples listed below as the recipient's address.
3. Send the e-mail.
4. Error: “Please correct the invalid addresses: …”

According to Wikipedia, all of the following e-mail addresses are valid, but Tuta accepts none of them:

• john.smith(comment)@example.com
• (comment)[email protected]
• john.smith@(comment)example.com
• [email protected](comment)
• " "@test.example.org
• "very.(),:;<>[]".VERY."very@\ "very".unusual"@strange.example.com
• postmaster@[123.123.123.123]
• postmaster@[IPv6:2001:0db8:85a3:0000:0000:8a2e:0370:7334]
• _test@[IPv6:2001:0db8:85a3:0000:0000:8a2e:0370:7334]

Notably, when entering " "@example.org, Tuta misinterprets it as "@example.org but still successfully sends the e-mail. When using a sub-domain, however, such as " "@test.example.org, Tuta also attempts to send the e-mail but then sends back an error message that reads:

We're sorry but the following e-mail could not be delivered.
Date: Dec 9, 2024, 8:57:32 PM
Recipients: "@test.example.org
501 5.1.3 Bad recipient address syntax

Expected behavior

Tuta should accept all valid e-mail addresses without complaining.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Desktop Environment, if applicable (on Linux)
• Version [e.g. 22]

Additional context

none

[hrb-hub]

Hi @realpixelcode , thank you for the report and effort you've put into this!
While your point is valid, I'm afraid that there are no current plans to address this issue, as the provided examples are not supported by most email providers. However that is not to say that it won't be addressed in the future.

Closing the issue for now, thanks again :)