Before CivicPlus can update your site to send email using your domain, you will need to configure your site to send email through your mail service.
All emails sent through Notify Me® or CivicSend must come from listserv@civicplus.com unless your organization would like to use a sending service of your choice that supports SMTP relay.
Important Note:
To update your site's sender email address, the email must be sent through an email service that you control. This is required because of email validation standards such as DKIM, SPF, and DMARC.
Make sure your email service supports bulk email and the required email authentication methods. These include SPF, DKIM, and DMARC. SPF helps protect against domain spoofing. DKIM uses digital signatures to help prevent sender impersonation. DMARC helps protect against forged email messages.
If you configure your site to send email through your own email service, CivicPlus no longer tracks bounced emails. You are responsible for removing invalid email addresses from your mailing lists.
Enable SMTP Properties
If you want to proceed with this setup, contact our Technical Support team. They will enable the SMTP configuration properties you need to complete the setup. SMTP settings will not take effect until support enables it.
Once enabled, System Administrators will see the SMTP options in Site Properties and can proceed with the setup.
Setup Instructions
Navigate to Modules, select Site Tools, and select Site Properties:

Locate the SMTP fields and configure the information:

SMTP Network Client Domain: Use the IP Address in the initial SMTP protocol to request to connect to the SMTP mail server
SMTP Network Enable SSL: Specifies whether to use SSL to access an SMTP mail server
SMTP Network Host: Specifies the hostname of the SMTP mail server to use for SMTP transactions
SMTP Network Port: Specifies the port number to use to connect to the SMTP mail server
SMTP Network User Password: Enter the password to use for authentication to the SMTP mail server
Note:
This field will appear blank for privacy reasons after you save your changes.
Confirm SMTP Network User Password: Confirm the SMTP Network User Password
Note:
This field will appear blank for privacy reasons after you save your changes. This field must exactly match the SMTP Network User Password above.
SMTP Network Username: Enter the username to use for authentication to the SMTP mail server
Click Save Changes:

Once you have completed the SMTP configuration, contact Technical Support. Provide the email address you want to use as the "From" address and when you want the cutover to occur. You can then test the mail flow.