title: Symfony mailer - sendgrid ip pools
body: <p>I am currently using symfony mailer + sendgrid to send mails. The configuration is rather standard (as described here: <a href="https://symfony.com/doc/current/mailer.html" rel="nofollow noreferrer">https://symfony.com/doc/current/mailer.html</a>).</p>
  
  <p>I am now trying to integrate sendgrid ip pools (so we can use different dedicated ips for different type of mail or customer, allowing them to better flag important mails and us to have better reporting). The pools are generallydescribed here: <a href="https://sendgrid.com/blog/ip-pools-all-you-need-to-know/" rel="nofollow noreferrer">https://sendgrid.com/blog/ip-pools-all-you-need-to-know/</a>.</p>
  
  <p>The problem is that the sendgrid bridge doesn't seem to support this feature (or maybe I'm missing it?). Also it seems (not sure) that the sendgrid implementation uses the sendgrid smtp api, not the sendgrid webapi and I have no option to add any kind of new/custom header in which to specify the pool.</p>
  
  <p>So how can I use sendgrid ip pools in symfony? Is there any option I can use in mailer to do that or do I need to make something custom (I have no problem with that, but I kind of like symfony mailer abstractization and would've enjoyed keeping it)?</p>