Grad School Letters of Recommendation

Hi all,
I'm graduating from a distance learning program within the SUNY system and I'm applying to both b&m and online grad school programs. My question pertains to letterheads for recommendations. Two of my recommenders are only with the school part time, which surprised me because they have doctorates and seem to teach each semester. They subsequently submitted very strong, effective letters of recommendation, but lacked the letterhead because they are adjuncts. Does anyone have any experience with this? Will some programs look at this unfavorably.Thanks in advance for any guidance,