> For the complete documentation index, see [llms.txt](https://help.checkoutchamp.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.checkoutchamp.com/crm/plugins/smtp-maintenance.md).

# SMTP Maintenance

SMTP is used to send your customers their order related emails such as Order Confirmation, Tracking Number Assigned, Fulfillment Shipped, Refund/Void notification, and several other events.\
\
Below you will find articles for our integrated Email Service Provider plugins.

* [Sendgrid SMTP Profile](/crm/plugins/smtp-maintenance/sendgrid-smtp-profile.md)
* [Maropost SMTP Profile](/crm/plugins/smtp-maintenance/maropost-smtp-profile.md)
* [SMTP Maintenance Setup](/crm/plugins/smtp-maintenance/smtp-maintenance-setup.md)

{% hint style="warning" %}
Be sure that your SMTP host whitelists these IP addresses:

* 44.219.22.112
* 52.206.5.84
  {% endhint %}

More autoresponder setup instructions can be found [here](/crm/crm-setup/campaign-setup/auto-responder-setup.md)!