Domain name registration.

I am currently supporting multiple small business sites. They do not host any web services nor their own e-mail etc. I am setting up some new routers for them and wanted to receive intrude log status etc through e-mail. To do this, I have to setup the domin name on the router setup etc. Becasue there is no registered DN, what do I put there? I guess that I could register a dynamic DN, but should I? I am not sure what to do here. Is it worth registering a DDNS, if not, what do I add to this section?

TX,

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