Make EHLO SMTP parsing exceptions that are caught sound less alarming in the logs

[ehyoitsdavid]

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

Thunderbird for Android

App version

9.0

Where did you get the app from?

Google Play

Android version

14

Device model

SM-S911W (Samsung Galaxy S23)

Steps to reproduce

1. Go to Thunderbird app
2. send any email
3. open logcat apps or check adb logcat
4. See the logcat contains this EHLO parsing exception for not just one provider but multiple providers

Expected behavior

Correctly parses SMTP server banner lines like

SMTP <<< 250-disroot.org
SMTP <<< 250-PIPELINING
SMTP <<< 250-SIZE 73400320
SMTP <<< 250-ETRN
SMTP <<< 250-AUTH PLAIN LOGIN
SMTP <<< 250-AUTH=PLAIN LOGIN
SMTP <<< 250-ENHANCEDSTATUSCODES
SMTP <<< 250-8BITMIME
SMTP <<< 250 CHUNKING

Actual behavior

See the logcat contains this EHLO parsing exception for not just one provider but multiple providers

[04-11 16:37:18.953 1931:1969 V/SmtpTransport$logger]
Ignoring EHLO keyword line: AUTH=PLAIN LOGIN
com.fsck.k9.mail.transport.smtp.SmtpResponseParserException: EHLO keyword contains invalid character
	at com.fsck.k9.mail.transport.smtp.SmtpResponseParser.parserError(SmtpResponseParser.kt:414)
	at com.fsck.k9.mail.transport.smtp.SmtpResponseParser.checkAndNormalizeEhloKeyword(SmtpResponseParser.kt:138)
	at com.fsck.k9.mail.transport.smtp.SmtpResponseParser.parseEhloLine(SmtpResponseParser.kt:122)
	at com.fsck.k9.mail.transport.smtp.SmtpResponseParser.readHelloResponse(SmtpResponseParser.kt:108)
	at com.fsck.k9.mail.transport.smtp.SmtpTransport.sendHello(SmtpTransport.kt:303)
	at com.fsck.k9.mail.transport.smtp.SmtpTransport.open$smtp(SmtpTransport.kt:104)
	at com.fsck.k9.mail.transport.smtp.SmtpTransport.sendMessage(SmtpTransport.kt:346)
	at com.fsck.k9.backend.imap.ImapBackend.sendMessage(ImapBackend.kt:146)
	at com.fsck.k9.controller.MessagingController.sendPendingMessagesSynchronous(MessagingController.java:1549)
	at com.fsck.k9.controller.MessagingController$5.run(MessagingController.java:1434)
	at com.fsck.k9.controller.MessagingController.runInBackground(MessagingController.java:226)
	at com.fsck.k9.controller.MessagingController.-$$Nest$mrunInBackground(MessagingController.java:0)
	at com.fsck.k9.controller.MessagingController$1.run(MessagingController.java:166)
	at java.lang.Thread.run(Thread.java:1012)

Logs

thunderbird-logs.txt

[ehyoitsdavid]

Looks like this issue only affects some small providers, not huge ones like Gmail and Outlook

this is a logcat example using the outlook SMTP server to send with all public IPs, sender, recipient and credentials redacted

[kewisch]

It appears we have a test for many of the lines you mention:

thunderbird-android/mail/protocols/smtp/src/test/java/com/fsck/k9/mail/transport/smtp/SmtpResponseParserTest.kt

Line 171 in 537c7d4

fun `read EHLO response with invalid keywords`() {

Are you sure there is an actual error occurring, or is it just a logged exception that is caught? Can you figure out more which line exactly is causing the issue?

[ehyoitsdavid]

@kewisch Thank you for the response. I do not know this is expected behaviour or not, and in the logcat it only shows up when the logging level is set to VERBOSE, so it does not affect end user experience. To clarify, this is only an exception, not an error.

And as an end user regretfully I am unable to pinpoint the exact line, especially on a Google Play release without debugging.

I sincerely apologise. You may proceed to close this issue if you think it is not a bug. Thank you.

[kewisch]

No need to apologize! I think it would be a good first bug to make this sounds less alarming in the log. I'll leave it open for a bit in case someone wants to pick it up.

[cketti]

See #8715 (comment) for additional context.