The answer is NO unless the limit is set by your email provider. So if your email provider has a limit of 70 recipients, in Mailbird you will also only be able to send to 70.
Mailbird is not deigned to be a bulk email solution. Mailbird is more of a direct replacement for the likes of Windows Mail, Outlook and Thunderbird.
You will want to look at Mailchimp, Madmimi or perhaps Sendgrid for a bulk email solution.