Our Sages in several contexts emphasized the importance and value of the Misva of Hachnasat Orehim – welcoming guests. The Gemara comments that Hachnasat Orehim is even greater than "Kabbalat Peneh Shechina" (greeting the Shechina). Elsewhere, the Talmud teaches that a place where guests are not welcome will be destroyed, just as happened to the sinful city of Sedom, where hospitality was not allowed. Furthermore, the Mishna in Pe’a includes Hachnasat Orehim in its list of Misvot for which one is rewarded both in this world and the next. And other sources mention many Berachot that are earned through this Misva, including children, rain in its proper time, longevity, and others.
Among the Halachic issues that arise when hosting guests is whether the hostess is permitted to pour wine or other alcoholic beverages for a male guest. We know that when a wife is a Nidda, she is not allowed to pour wine or other alcoholic beverages for her husband, unless she does so in an abnormal manner (such as by pouring with her left hand if she normally pours with her right). According to some Halachic authorities, this applies also to a married woman serving a man other than her husband, and thus a hostess should not pour for her male guests in the interest of modesty. By contrast, the work Ezer Mi’siyon writes that this restriction applies only to a married couple when the wife is a Nidda, and a hostess is permitted to pour alcoholic drinks for her guests.
In practice, Rav Shayo, in his work Petah Ha’ohel (p. 87; listen to audio recording for precise citation), rules that generally a hostess should not pour wine for a male guest, and if she does, the guest should ensure not to look at her as she pours. However, if the hostess is hosting a large meal, with many guests around, then according to some Halachic authorities it is permissible for the hostess to pour for her guests.
Summary: Generally speaking, a hostess should not pour wine or other alcoholic beverages for a male guest, unless she is serving a large meal and there are several other people at the table with them.
