i know the benchmark, you can have 3 lists, all sent from 3 different companies, and if someone opts out, they get the choice if they are listed on other lists, to tick all the lists they are on, or just some. Does aweber and mailchimp do this? I have emailed mailchimp several times with the question but no answer yet, i am pretty sure they do not, so if someone opts out it is just an opt out from that list.
Never send an email without making sure it’s working properly. What looks good in your inbox can look broken or mangled in someone else’s. Use tools that can help you with testing your SPAM score, deliverability and the rendering of your email. There are plenty of free or freemium solutions that provide screenshots of your email in dozens of different email platforms.
Think about implementing referral links to incentivize your subscribers to spread awareness about your brand, too. Referral links allow your current customers to promote trackable links for your business. In exchange for sending new paying customers your way, you can give them incentives like discounts, coupons, vouchers, cash, prizes or redeemable points.