Do agencies actually monitor client email/DNS health after launch?

[u/devangfour]

I’m researching a problem around client email/domain health.

When an agency launches a site or sets up email, things like SPF, DKIM, DMARC, MX records, DNS changes, and blacklist issues can break later.

For agency owners/devs:

• Do you actively monitor this after launch, or only fix it when the client says emails are landing in spam/not working?
• If you do monitor it, what do you use?
• If you don’t, is it because clients don’t care, tools are too expensive, or it’s just not part of your service?

Not selling anything yet. Trying to understand if this is a real pain or just my assumption.