Q. Can one that is travelling immediately after davening Shacharis and won't be able to say goodbye then to his nearby friends in shul, give his farewell greetings and wishes before davening?
A. Horav Dovid Pam Shlit’a maintains that if they are seating close by and he doesn’t use the Shalom name it is permitted.
Horav Shlomo Miller’s Shlit’a opinion is similar.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu Shlit’a and Horav Kalman Ochs Shlit’a.