Either build in SMTP or using 3rd party SMTP
- Look into using 3rd party providers (e.g Elastic Email, Sendgrid) before deciding to build your own SMTP (Lots of scammers / waste of time)
Unlimited Subscriber
- Unlimited subscribers is different than unlimited mailing, There is a difference between contacts and how many emails you send. Its better to send more emails to less contacts than just spreading your content all over the ESPs. And it will be cheaper too. (Unless you decide to get your own SMTP then contacts/subscribers amount doesn't matter)
Analytics and Report Tracking & With Autoresponder
- Any decent mailer precomes with all that don't worry about it (e.g acellemail, mailwizz, interspire)
Low budget, prefer cheaper solution or 1-time payment
- There is no such thing as 1-time payment for SMTP, Mailer yes, SMTP or mailing anyway no. As in for cost it depends on how many emails you want to send, If you intend to send more than 10k a day i recommend getting your own SMTP it will be cheaper and not a pain in the ass struggling with 3rd party providers ban, limitation,etc
And remember to validate your list and change your content frequently
