you need to have many private proxy addresses for creating email accounts through a bot.
otherwise, If a bot is going to use public proxies, then Email provider(gmail/ymail/outlook) can detect and ban/block your email accounts(due to multiple login from from different range of IPs) in a few days , also maximum public proxies are already blocked or being blocked in minutes.
Since you want to use those emails for long purpose,so only creation of an email account is not end