What is it?
The E-sign feature is available from IFS Cloud 23R2 (Cloud deployment only, Remote currently not supported). At its core it's an integration between IFS Document Management ("Docman") and Adobe Acrobat Sign.
In order to send a document for signing you need to first upload it to Docman, release it, and attach it to some screen/business object. For details on the process, watch the video linked below.
https://www.youtube.com/watch?v=Aed1j9VOPDU
Agreements/envelopes
When you send a document for signing to one or more recipients an "agreement" is created in Adobe Sign. The agreement acts like a container for the document and the list of recipients, and supports the whole flow from sending, signing and retrieving the signed document. As of 24R2, you can only send one document per agreement. An agreement in Adobe Sign is what other E-sign solutions sometimes calls "envelopes."
IFS keeps track of every agreement that has been created and, to use a term that's more known and to keep the possibility of integrating with other providers, we are also using the term "envelope" inside IFS.
My customer needs to send 10 documents for signing every week - how many agreements do they need?
Since 1 document sent for signing = 1 agreement used, the customer needs one agreement per document they want to send for signing. This is regardless of how many recipients sign the document.
Agreements are sold in packs of 100 and they are valid for a month. An agreement never expires but IFS keeps track of how many agreements are used and compares that with the number of agreements a customer has bought. If a customer uses more agreements than they have paid for, then can expect a sales person calling them, asking if they want to buy another pack
To answer the question above, the customer needs 10 agreements per week x 4 weeks = ~40 agreements per month = 1 pack of 100 agreements per month.
Does the customer need to create their own Adobe accounts?
No. When a customer orders the E-sign feature, an Adobe account is automatically provisioned and connected to IFS's master Adobe account.
Can a customer use an already existing Adobe account that they have created themselves?
No.
Is there any documentation?
Yes!
About E-Sign - https://docs.ifs.com/ifsclouddocs/24r2/SearchForAndUseDocument/AboutESign.htm?StandAlone=true
E-sign process model - https://docs.ifs.com/ifsclouddocs/24r2/ProcessModels/Process_Model/SendandReceiveDocumentforESign.htm?StandAlone=true
(click the green boxes/activities to read about each step)