Getting recipients to add you to Safe Sender list


New Email

Question about ways to get recipients to add you to SAFE SENDERS LIST.
I’ve seen many mailers include mailto: links in their headers referring to their own sender address. I imagine their goal is that either:

1)Recipients have a ESP (eg. Gmail) that automatically adds any address they reply to to contact list, and this facilitates delivery to inbox instead of SPAM

2) Recipients copy/paste address into Contacts manually

Any feedback on the effectiveness of (1) ? I heard Gmail changed and now only adds addresses you reply to to “Suggested Contacts”. What degree of advantage does being in “Suggested Contacts” for delivering to Inbox VS Spam? Does Yahoo auto-add to contacts, and does this help? I know Hotmail disables mailto: links so this solution (1) would not work, only (2).

I know there are more time-consuming and effective options such as Manually adding to Safe Senders list (Hotmail), manually adding to Contacts (Gmail) or creating Filters for safe domains (Yahoo). For me question is: more time/less automatic such a solution, the less adopted it will be. So I’m thinking, offer a quick/low-effectiveness solution (auto-add to contacts by reply) or the more lengthy / effective one with full list of instructions per ISP to add to Safe Senders? Or both?

Good starting point is knowing: does auto-add to contacts even work in Gmail and Yahoo and is it effective to increasing inbox delivery?

Any help appreciated.