Emails Being Blocked - Base64 encoding

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sjgarth
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Emails Being Blocked - Base64 encoding

Post by sjgarth »

Hi,
I have read many previous posts but there is no suitable solution to this.
I have the latest version of PHPBB, and use SMTP as my hosting company has disabled php mail, they also use Barracuda anti-spam checker.
More and more hosting companies are tightening up on anti-spam measures ,and the one that has tripped me up is 'Unnecessary base64 encoding' of email headers.
As far as I can tell phpBB always encodes the following headers in Base64, To, Subject, From and Reply-To.
This is triggering Spam Assassin and Barracuda anti-spam software (maybe more but I haven't come across them yet).
It wouldn't be difficult for the PHPBB coding team to change it to only encode if it is necessary, other packages do this.
Anyone know a fix for this issue other than the 'change hosting company' useless answer?
Steve Garth
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rxu
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Re: Emails Being Blocked - Base64 encoding

Post by rxu »

There's a bug report for this: https://tracker.phpbb.com/browse/PHPBB3-15729
Those headers could be probably left without Base64 encoding if within ASCII range.
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thecoalman
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Re: Emails Being Blocked - Base64 encoding

Post by thecoalman »

Email spam filters typically use scoring system and the encoding issue typically doesn't score very high. You may have other issues, bad or no SPF record topping the list. Register an account using this service:

https://www.mail-tester.com/

While on the topic there was at least two recent topics where users were having trouble with the content of the subject, specifically "topic reply
Notification" was blocking them from being sent.
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sjgarth
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Re: Emails Being Blocked - Base64 encoding

Post by sjgarth »

The Base64 issue costs 1.75 points and the other minor issues kick the email over 2, which my hosting company has set the filter to. I have checked and other hosting companies have lowered their filter threshold as well.
That said, the issue IS with PHPBB for encoding where it is not needed.
Steve Garth
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rxu
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Re: Emails Being Blocked - Base64 encoding

Post by rxu »

sjgarth wrote: Sun Aug 01, 2021 4:07 pm That said, the issue IS with PHPBB for encoding where it is not needed.
Could you test if this patch will change anything on that matter?
https://github.com/phpbb/phpbb/pull/6258/files
sjgarth
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Re: Emails Being Blocked - Base64 encoding

Post by sjgarth »

Hi rxu
Thanks for this, I have made the changes and everything seems okay.
I am able to send emails to myself and a test user. I have managed to send the forgotten password email to myself, but it would not send it t omy test user. It may be to soon after the previous one, I will try again in an hour.
However, I am unable to check with anyone else as yet.
If I get an a notification I will let you know.
Steve Garth
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thecoalman
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Re: Emails Being Blocked - Base64 encoding

Post by thecoalman »

@rxu, thanks for the patch. I have been seeing this warning for years now on email tests. Haven't tested it but I have confidence it works. :D
sjgarth wrote: Wed Aug 04, 2021 6:18 pm I have managed to send the forgotten password email to myself, but it would not send it t omy test user.
AFAIK the eail for a reset password is sent immediately, it's not queued and even if it was it shouldn't be more than a few minutes. The only thing that may slow it down or block it would be your host.

Do theses accounts use the same domain?
“Results! Why, man, I have gotten a lot of results! I have found several thousand things that won’t work.”

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sjgarth
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Re: Emails Being Blocked - Base64 encoding

Post by sjgarth »

Hi,
My own email is on the same hosting account, but different domain.
My test account is on outlook.com.
Password reset email is received on my own account, but not at outlook.com account (I have just tried again).
I have not received any ' your email was blocked' messages, but they sometimes take a while.
It will send a test email (from the email settings page) to the outlook.com account, but it will not send a forgotten password email to outlook.com.
So, the PHPBB system will send a forgotten password to my email, but it will not send a forgotten password email to my outlook.com email. Email tracking by my hosting cpanel shows that the outlook.com email was never received from phpbb. This is clearly now not an encoding problem.
Last edited by sjgarth on Wed Aug 04, 2021 10:16 pm, edited 1 time in total.
Steve Garth
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thecoalman
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Re: Emails Being Blocked - Base64 encoding

Post by thecoalman »

sjgarth wrote: Wed Aug 04, 2021 9:52 pm Hi,
My own email is on the same hosting account, but different domain.
My test account is on outlook.com.
I'd suggest you try the email tester I linked to above. Using the email address they provide register an account on your forum.

You won't get a perfect score, minimally it will complain about the content as it's common and some filters will flag it. The biggest things you are looking for is rDNS, SPF and DKIM.
I have not received any ' your email was blocked' messages, but they sometimes take a while.
These are not always sent. If it's rDNS issue they get dropped into a blackhole.
“Results! Why, man, I have gotten a lot of results! I have found several thousand things that won’t work.”

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sjgarth
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Re: Emails Being Blocked - Base64 encoding

Post by sjgarth »

Using the email tester, forgotten password email not received (and not sent from PHPBB to my hosting email tracker).
Test email from email settings page was received and scored 10 out of10. A while back I ensured the SKF and DKIM settings were correct.
Using user registration, emails were sent successfully to the outlook.com email and others.
I believe the base encoding issue to be solved by the fix from rxu, this seems to be that the software is not sending the forgotten password emails at all.
Steve Garth
A complete idiot who requires a forum like this to tie his shoelace.
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