Yes! Warmup is truly unlimited. The only sending cap is on the number of emails sent per month, which is determined by the tier of your plan.
We have a lot of experience with this. We have developed an algorithm which optimizes warmup to maximize your sender reputation. If you don't believe us, just check the stats on your dashboard when you login!
Most email services these days are very careful about identifying emails outside of a person's contacts. If you want the best results, it is very important to increase your sender reputation before an email campaign, or you may get a lot of bounced emails, or land in spam.
No, Warmup is a separate process from your active email campaign. Warmup does not "spam" your leads. We value partnerships and businesses when they are trying to find real solutions for their clients. That's why we cap the number of emails sent every month - to prevent "spamming". In addition, your outreach is tightly controlled by your campaign objectives. You choose how many follow-ups to send, and when to send them.