I am assuming you are trying to do cold email marketing based on your fear of being unsubscribed.
You either need to pay for a service or put in the work yourself.
Free often means putting in the work...
FREE:
Mailchimp / Brevo / whatever free platform you want
These have free tiers but you will need to be managing multiple accounts and constantly rebuilding your contact list.
You will be limited to sends per day, but you will have the automation in place to easily send bulk sets of emails. Each platform has their advantages and disadvantages. Figure out which advantages you want to work for you and which ones you don't mind working for.
gMail
Lot of work ahead..But it can be done.
(Ideally, you buy aged Gmail accounts as was suggested previously. )
But for FREE..You'll be churning and burning accounts. Create a ton of accounts. Manually send the emails one at a time.
Go slow to start low. Enjoy the grind.
TIP:
Send an initial dummy email with "This is my offer if you are not interested email me back to unsubscribe" and get some fake engagement
PAID:
Platforms offer the automation needed to make cold emails look authentic.
Many cool cold email automation platforms are available, and they all have different features and price points.
Some systems promise 100k/mo email sends for as low as $200, but you'll find that most of these emails are never reaching an inbox.
Others are more expensive and allow you to throttle the number of sends per day over a drip, but again you manage the risk of never reaching inboxes.
The best setup IMO is buying aged domains + premium email server + a warmup system + drip platform. Start with a warmup and go slow + start low on the drip. Open the drip to more per day as needed + monitor for failures. To avoid downtime during a burn, have backup domain(s) in place and ready to swap in.
This is not free and this is not cheap, but if you have a solid list you'll want every email to be received. If you have a valuable list of 20,000 contacts you'll want
Then again, if your list is bad, it doesn't matter too much. Blow the load, burn the list, take an axe to the domains, and do whatever you need to churn them out.
