domain removal

The only ways for a domain and all of its data to be removed are

a) complete account removal (available to the account's Owner user in Preferences or via Support action upon verified Owner request only)

b) manual use of the 'delete' functionality in the menu next to each domain in the Domain Overview

c) use of domain deletion functionality in the API (Enterprise accounts only)

There is currently no logging performed for these actions.

A subdomain which was added automatically (because it appeared in DMARC reports) may stop being shown in the Domain Overview if the subdomain does not receive new data for a 7 day period (the domain will reappear if new data is received), but the data for the subdomain traffic is still available in the Detail Viewer.

If the intent of a domain (or subdomain) removal is to have it never reappear, you must update DMARC records so that new traffic is not sent to your dmarcian account!

In the case of a subdomain, this may mean that you have to add an explicit new complete DMARC record at that level, e.g. "v=DMARC1; p=reject; rua=mailto:mydmarcreporting@customerdomain.com;" if you wish to see reporting, or even just "v=DMARC1; p=reject;" to have policy enforcement but no reporting (not recommended).

Bear in mind that due to lags in DNS propagation and potentially some other issues at reporting entities, new data could still be sent to your account for some number of days after the DMARC record is updated on your DNS.  If this occurs and the domain reappears, simply delete it again.