By default we install a plugin called Easy WP SMTP on all new sites hosted with S4 and set it up to send transactional emails from your website through our SMTP server.
If you use an alternative email service like G Suite, or if you send a large amount of transactional email from your website and want to use a third-party SMTP service like Sendgrid, then you will need to change the settings to fit with that SMTP service. They will provide you with instructions on how to do this.
If you host your mail with us then you still might want to change some of the settings, you can do this by logging into your wordpress admin panel at yoursite.com/wp-admin.
Find Settings in the menu on the left, followed by Easy WP SMTP.
The settings that you might want to change are all on the first settings tab – SMTP Settings. You can change the Name, From Address, etc. and SMTP server User and Password to those of any email address that you have hosted with us.
If you change the Port Number from 587 your site will not be able to send email. We also strongly recommend that you do not uncheck the Encrypt Password box.
Be sure to Save Changes before leaving and it is always a good idea to send a test email to make sure that everything is working as expected. You can do this from the third settings tab – Test Email.