A marja` was asked the following question:
As-Salaamu `Alaikum wa Rahmatullahi wa Barakatuh,
I am a young man that has been residing in Spain for a quite a fear years. It is a longstanding custom in this land that when people meet and greet one another, the men and women shake hands and kiss each cheek of his or her friend once.
Upon my first coming to this land, I had only recently arrived when a Spanish woman came to greet me and kissed me on the side of the face. This was a cause for many things that came into my mind among the people. Whenever this happened, I did not have the time to explain to them why this should not be done and why I avoided it. The next time this form of greeting took place, I pulled my face away from her.
In fact, I used to delay the meeting and greeting with the women the first time and whenever I had an opportunity to explain to them about the matter I would do so. I explained that I will never great them in this fashion and even went into detail on why this was the case and that my religion does not permit me to do this act.
Naturally, I would like to make clear that my stopping this action is neither a cause for me to become arrogant nor to hold women in low rank. In fact, my position is the opposite. After I followed this way of understanding, I was able to lift this difficulty without it being a cause of them rebuking me or going away from me on account of my being Muslim.
This is also a means for them listening to me and I have a doubt in the legality of doing the first thing, i.e. the kissing on the cheek and that which I am currently doing. Which of these should I be doing in reality?
I hope that you can guide me to the right path and the correct understanding so that we might agree upon it and cooperate in the good.
The marja,` Imam `Abdur-Rahman Ash-Shami, may Allah preserve him, said the following:
It is impermissible to greet women in the way in which you mentioned in your letter. It is impermissible and should neither be done on one cheek nor on the other in the case of members of the opposite sex.
The most important thing that could be mentioned is that it is compulsory for you to think about a way to leave from that society so that you do not fall under the ruling mentioned of people Allah said of them,
Those who the angels take in death while they are oppressing themselves they shall have the angels question them, “What was your state?” They shall respond, “We were weak in the land.” The angels shall reply, “Was not the Earth of Allah spacious enough so that you could have emigrated…”
An exemption to this would only be if you were residing in the land under real necessity. In this case, the threat mentioned in the ayah would not apply to yourself. Let it be the case that you seek counsel in a trustworthy scholar – firm and wise in his knowledge and his religion – so you can take your next course of action. And may Allah pardon us and you! Amin.
Taken from the website of the maraji`
 trans note: The Shaikh here is making note of the fact that men greeting eathother in this fashion is permitted as this is a common greeting among Arabs, Jews, Sicilians and the like and implies no immediate sexual intent.
 Surat un-Nisa,’ ayat 96-97