I got a "Have another try" mail yesterday, inviting me to rejoin Ingress while having a current sojourner of 1300+. See
Your not the only one as i get them too...it seems to happen for me after talking with in app support and they ask for an alternative email address to contact you on,this then seems to generate the emails.
Sometimes they are handy to have with codes though,my alternative has never been used on Ingress to setup an account.
Next one: "👀 See unique Portal visits"