I've been submitting a few commercial property lawn mowing bids. After they request a bid I go over, meet them and ask them what they want, and then mail them the estimate with a prepaid postage envelope to mail back to me. I'm wondering if it's good/bad policy to call them back and see if they had any questions? Or would that be pestering them? I'm sure they are very busy but don't want my bid to get forgotten about either. Any suggestions?