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README.md

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+# Special Announcement
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+We have released a [v3 beta branch](https://github.com/sendgrid/sendgrid-php/tree/v3beta) for this library that supports our new v3 Mail Send endpoint which is in open beta. The v3/mail/send/beta endpoint is not a production endpoint, so you should not integrate with it for your production email sending. However, when we make this an officially released feature it will be available at v3/mail//send.
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+Please try it out and let us know what you think about the endpoint and the library in the [issues area of this repo](https://github.com/sendgrid/sendgrid-php/issues), all of your feedback will be taken into account to influence the endpoint and this library.
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+Beginning with v3/mail/send/beta, the new version of our library will only support v3 endpoints.. Once this endpoint is out of beta, we will update the endpoint, removing the “/beta” from the URI. At this point, the v3 beta branch will be merged to master and will be our official library going forward. This means that we will no longer formally support the v2 mail.send.json endpoint in any of our libraries.
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+So long as you are not automatically pulling new versions of the library into your production code base, your integration will not break regardless of which endpoint you’re using. By the way, don't pull new versions into your production code base, because breaking changes break things.
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+The /api/mail.send.json endpoint, known as v2 mail send, is NOT going away. It will continue to work as it always has, happily sending your emails along as if nothing happened.
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 # SendGrid-PHP
 
 This library allows you to quickly and easily send emails through SendGrid using PHP.