The primary UTM parameter you need to focus on to monitor and segment traffic originating from your email marketing campaigns is utm_medium.
When creating links within your emails, ensure to consistently use utm_medium=email. This tag signals to your analytics tool, such as Google Analytics, that the visitor landed on your site through the email channel.
While utm_medium=email identifies the channel, you can then utilize utm_source to provide more specific information about the email source. For example, you could use utm_source=may_newsletter or utm_source=product_update_email in conjunction with utm_medium=email.
By filtering or segmenting your traffic by Medium: email in your analytics reports, you’ll be able to view all the traffic and interactions attributed to your email marketing, irrespective of the additional utm_source or utm_campaign values you’ve applied.
Other parameters like utm_campaign, utm_content, and utm_term offer supplementary details. utm_campaign names the particular campaign, utm_content helps differentiate between various links within the same email, and utm_term, though less common in emails, can identify specific segments or keywords if necessary.
To directly address your query, utm_medium=email stands as the foundational tag for recognizing, monitoring, and analyzing traffic from the email channel overall.
Best regards,
Sean