Unfortunately WHMCS does not support SRV and CAA entries by default. Since several customers have asked for it, we have added support, but template customization is necessary.
If you want to offer SRV and CAA DNS entries, please proceed as follows, open the file /templates/YOUR_TEMPLATE/clientareadomaindns.tpl.
Search this line:
<option value="AAAA"{if $dnsrecord.type eq "AAAA"} selected="selected"{/if}>{lang key="domainDns.aaaa"}</option>
And add below:
<option value="SRV"{if $dnsrecord.type eq "SRV"} selected="selected"{/if}>SRV Record</option>
<option value="CAA"{if $dnsrecord.type eq "CAA"} selected="selected"{/if}>CAA Record</option>
Search this line:
<option value="AAAA">{lang key="domainDns.aaaa"}</option>
And add below:
<option value="SRV">SRV Record</option> <option value="CAA">CAA Record</option>
After you have done the changes, your clients are able to create SRV and CAA records.