...unless you use OVH: €2.99 and €7.99 respectively but deliverability might be a problem
company setup:
Hardware: main server: i5-3570/8GB RAM/2 x 240GB SSD; backup server: i5-2500/8GB RAM/2 x 240GB SSD
Software Backend: Postfix, Dovecot, Amavis-New, SpamAssasin, ClamAV, Postgrey...