The Gemara in Masechet Berachot, Daf Nun Chet (page 58), is very famous. I see my friend after 30 days. I bless him that we are alive. Somebody who sees his friend after 30 days says the blessing that we are alive. And if he sees him after Yud Bet Chodesh (12 months of not seeing him), I bless him that we are alive. If he sees him after 12 months of not seeing him, he says the blessing that we are alive.
First, Tosafot and the Rosh clarify that this is not just somebody you have not seen, because there are a lot of people we do not see and then see again. The connection you have with that person really matters. We are talking about somebody who is very dear to you, and you are very happy when you see this person. And therefore, that is when the Shulchan Aruch brings it in the Pesak (ruling). There, it sparked a little bit of a discussion among the Poskim (halachic authorities).
How do you know? The world is very tricky. Relationships are complex, and sometimes you think that somebody likes you or that you have a good relationship with somebody, but really, inside, you know, time will tell. I didn't say Shehecheyanu (that we are alive) when I saw you. Well, I saw you three weeks ago somewhere. Several Poskim raise this point and say, “Look, this is part of the Pesak.” Would that create enough of a safek (doubt) not to say the Beracha (blessing)? The answer is yes. At some point, the Poskim said that we do not know how to say this Beracha with Shem u'Malchut (the Name and Kingship) because of this point. We do not know what a person is feeling inside. You may think that they like you, but really they do not. So that was the Pesak.
Hacham Ovadia disagrees. He says, “It’s true, it could be, but if you’re certain that a person likes you...” There are still some genuine people out there. Very few, but there are. If you’re certain that these are the people you are seeing, then you could say the Beracha. Or it could be a family member or somebody you truly know. In that case, one person would have to say the Beracha.
These days, it could be that you did not see the person physically, but you saw them through FaceTime, or, back in the day, through a letter, or you heard about them. Can you still say the Beracha? It’s interesting: you will not be able to say the second Beracha, the Beracha of Mechaye HaMetim, in two cases. Number one, if you heard that they are okay, if you heard that they are doing well, then for sure you cannot say the Beracha. The whole idea was that, theoretically, this person could have not been around. When you see them, you say, “Oh, Mechaye HaMetim,” because there was a Psak Din (halachic ruling) on Rosh Hashanah. I don’t want to get into that. But when you heard about these people, that Beracha does not apply. Hashem gave life to those who are dead. If you heard that the person was not dead, then there is no way to say it. If a year passed and you had really no connection, then yes.
There is another case in which you should not say this Beracha: if it hurts the person. A lot of people, if you said Mechaye HaMetim, would say, “What are you talking about? You know, it’s not...” Now, the answer is that you do not have to say the Beracha out loud; you can say the Beracha to yourself. If any of these cases applies, then you go down to the level of Shehecheyanu. There is a certain Simcha that is special when you see a person, when you hug a person you are very close with. It is something that you cannot do over the phone yet. In the meantime, since you cannot do that, that level of Simcha is sufficient to be able to say the Beracha, although there is a big discussion in the Poskim. If it added a lot of Simcha to you in this moment, then one should say the Beracha with Shem u'Malchut. B'kavod.