Free/Open source software (FOSS) is an important part of the IT ecosystem. Due to the voluntary nature of participation, continual recruitment is key to the growth and sustainability of these communities. It is therefore important to understand how and why potential contributors fail in the process of transitioning from user to contributor. Most newcomers, or "newbies", have their first interaction with a community through a mailing list. To understand how this first contact influences future interactions, we studied eight mailing lists across four FOSS projects: MediaWiki, GIMP, PostgreSQL, and Subversion. We analyzed discussions initiated by newbies to determine the effect of gender, nationality, politeness, helpfulness and timeliness of response. We found that nearly 80% of newbie posts received replies, and that receiving timely responses, especially within 48 hours, was positively correlated with future participation. We also found that while the majority of interactions were positive, 1.5% of responses were rude or hostile.