Is anime1.com a legal site for watching anime? Other anime streaming sites are blocking my IP because I'm Iranian while anime1.com isn't. I wanted to know if it's legal to watch/stream anime from this site. Thanks.
You might want to see this post: How can I tell if a site is Legal? It lists legal sites for streaming anime and reading/buying manga.

Is anime1.com legal? Nope. An immediate indicator that a site is illegal is if it's laced with ads that are usually irrelevant to anime/manga in general. anime1.com's anime pages are almost filled up with ads and clicking on anime episode links results to pop-ups.

'You can also check the site information to confirm if they have a valid certificate and connection type,' as mentioned by @Rumplestiltskin. If a green padlock is present, that site is most likely secure and a 'Connection is secure' message will pop out whenever you click on it. This helps you avoid 'really dangerous anime-scam sites.' anime1.com does not have this so be wary of sites like these.

Clarification: I just want to clarify something since people seem to misunderstand. The check for valid certificate is not a way to check for a site's legality. It is just for security purposes. There are many ways to check for a site's security but that, I think, is outside the scope of the question.