Yes, this is possible. We provide you with a list of current IP addresses for this purpose, which can be retrieved online via a DNS query. The IP address query is possible for both options of sending e-mails (for your invitation and reminder e-mails) via HeyForm for sending e-mails via the address book and for sending through your own mail server registered with HeyForm.
In general, you have various options for sending e-mails: you can send your invitation and reminder e-mails via the HeyForm sending system (address book, e-mail templates) or you can register your own mail server with HeyForm and use it for sending e-mails. Especially when using HeyForm’s own e-mail dispatch, an SPF (Sender Policy Framework) record is recommended in order to avoid e-mails sent by the HeyForm system being classified as spam and/or not reaching the recipient at all.
For the SPF record, we recommend a specific form: the release of all mail servers (“~all”) and not the release of specific IP addresses, as our IP addresses can change.