Undocumented breaking change in Mailer when upgrading from 5.5 to 6.x

[lucasvdh]

• Laravel Version: 6.0.4
• PHP Version: 7.2.21
• Database Driver & Version: not applicable

Description:

I am required to keep a record of all email messages which have been sent. It used to be that I could use the callback in the mailer (Illuminate\Mail\Mailer) to fetch the raw content of an email message (Illuminate\Mail\Message) so I could persist it to storage.

In Laravel 5.5 the callback given to the Mailer@send is ran after the body is set on the message.

Since Laravel 5.6 the callback given to the Mailer@send is ran before the body is set on the message.

This causes the body of the message to not be present in the callback. There is no documentation in the 5.6 upgrade guide about this breaking change that changes the callback from a "after"-callback to a "before"-callback.

Steps To Reproduce:

1. have a Laravel 5.5 project
2. send a mail
3. validate that the email body is present if you call ->toString() on the $message in the callback of Mailer@send
4. upgrade to Laravel 5.6+
5. send a mail
6. call ->toString() on the $message in the callback of Mailer@send
7. only the header and attachments are returned

Misc

This issue has previously been reported here: laravel/ideas#1646
This issue regards this PR: #22995
This issue regards this specific commit: 0cd8899

[driesvints]

Hey there,

Unfortunately we don't support this version anymore. Please check out our support policy on which versions we are currently supporting. Can you please try to upgrade to the latest version and see if your problem persists? We'll help you out and re-open this issue if so.

Thanks!

[petermein]

The not supported comment is great, but then there should be an upgrade guide from 5.5 to 6.x right?
Otherwise what is the point of LTS versions?

[lucasvdh]

@driesvints if you read my original description you would have seen that my current Laravel version is 6.0.4. I put 5.6+ in the description of the issue because this effects all versions from 5.6 and up.

[driesvints]

@petermein there's an upgrade guide for each version between 5.5 and 6.0. You're always free to send in a PR to one of those.

@lucasvdh but you mention

have a Laravel 5.5 project

Which we don't support anymore. So I didn't understand why you said that 6.0.4 in your issue template. If there's something missing from an upgrade guide, feel free to send in a pr to the docs: https://github.com/laravel/docs/

[Miguel-Serejo]

There is no documentation in the 5.6 upgrade guide about this breaking change that changes the callback from a "after"-callback to a "before"-callback.

While the upgrade guide could use an itemized index, I'd expect anyone who has trouble with mails after upgrading to ctrl+f the word mail: https://github.com/laravel/docs/blob/5.6/upgrade.md#mail

Mail
withSwiftMessage Callbacks

In previous releases of Laravel, Swift Messages customization callbacks registered using withSwiftMessage were called after the content was already encoded and added to the message. These callbacks are now called before the content is added, which allows you to customize the encoding or other message options as needed.