How to model a double opt-in registration business process model in BPMN?

Pro­cess description:

The Double Opt-In mod­el uses two steps to veri­fy the con­sent giv­en. Filling out the form on the site by the inter­ested recip­i­ent does not end the pro­cess of adding a new per­son to the list. Instead, it causes a mes­sage to be sent to the e‑mail address provided, con­tain­ing a spe­cially pre­pared link con­firm­ing the desire to register. At this stage, the sys­tem hand­ling the news­let­ter mail­ing already has the inform­a­tion provided in the form but has not yet sent the mar­ket­ing mes­sage. The per­son who joins the news­let­ter must con­firm his desire by click­ing on the spe­cial link gen­er­ated for him, which is sent to him in a return mes­sage. If he or she does not receive the email or does not con­firm his or her desire to sub­scribe to the news­let­ter, the gen­er­ated link will expire after a cer­tain peri­od of time. In turn, the acquired address will be deleted from the email sys­tem. Com­plet­ing the regis­tra­tion is pos­sible only by con­sciously open­ing the email and click­ing on the attached link. Only after these actions have been per­formed will the mail­ing sys­tem register the con­sent giv­en and trans­fer the per­son to the indic­ated group of recipients.

The file con­tains a descrip­tion and a pro­cess mod­el that you can use in soft­ware, Visu­al-Paradigm and any oth­er com­pat­ible with the XMI exchange format.

(Eng­lish and Pol­ish mod­el ver­sion available)