Its a long story but I've started getting emails that aren't sent to me i.e if my email was mrsmith@email.com I'm getting emails for mr.smith@email.com

At first I thought they were entering their email wrong but now I believe something is happening either with the ISP, or with the companies email is registered on.

The content of the emails is such that I know know a lot of info about the other person-address, phone number, bank details etc. This is just from reciepts from online orders etc, not me snooping.

I've contacted the other person who has accused me of hijacking their email, I've contacted ISP who said this could never happen. What do I do next?

gmail doesn't recognise any dots in an addy so in your example that's what would happen
They're effectively both the same address

So assuming that's the case who's "fault" is it? The ISP?

Another example

anotherexample@googlemail.com
anotherexample@gmail.com
another.example@googlemail.com
another.example@gmail.com

are all the same addresses far as gmail is concerned

I don't think gmail would issue mrsmith@gmail.com & mr.smith@gmail.com to separate accounts

Is this specific to gmail? My ISP is Talk Talk.

That's worrying if you're getting their email without know their password!
How long has it been happening? Does re-login into you accout make no difference?

I didn't believe the dot thing but I've just tested it with my own gmail account and it's true 🙁 How crap is that ?

Started about a year ago. Didn't cotton on for a while as a lot of it seemed like spam. It was only when I started getting receipts more recently that I realised they were for a different person.

I couldn't resist testing it either.

just did a reverse test and got:

Delivery to the following recipient failed permanently:

simon.f.barnes@an-email-provider-that-works-properly.co.uk

I can't see you have anything to worry about, unless they are getting your email! You've reported it, it's now up to the providers to investigate if they want to. It is the email provider that would be breaking any data protection laws unless you are publishing it elsewhere.

surely the most likely scenario is that they're are entering their email address incorrectly?

@googlemail.com
and

@gmail.com are not congruent

actually I'm wrong there, blahblah@googlemail.com arrives at blahblah@gmail.com …

Are you saying this is only an issue if the address is a @googlemail or @gmail address? Or are you saying it also affects any email address with a '.' to which email is sent from a gmail account? I'm confused and I have an email address with a '.' in 🙁

Gmail & googlemail are one & the same thing.
They can't use the GMail domain in the UK (and Germany, i think) due to some copyright infringement thing or something, but they do reserve the account names people take on both.
You can send an email to either domain & they go to the same account.

Are you saying this is only an issue if the address is a @googlemail or @gmail address? Or are you saying it also affects any email address with a '.' to which email is sent from a gmail account? I'm confused and I have an email address with a '.' in

Dunno – have you thought of trying it to see?

The dots being ignored are a feature to stop exactly this sort of thing happening. You CANNOT sign up for a gmail acct with a dot in the name and then have someone else have the same without the dot. It's less likely to cause issues with slightly dense people the way google do it than the way the relevant RFCs say email SHOULD be done. Edit and no, it doesn't affect outgoing.

Chances are, the person in question is a moron and has signed up for things on the wrong email address. My other half gets a load of email for someone and she's made a couple of attempts to get them to stop but no luck. In the end she just redirects them directly to delete.

I think the person with the other email address is an idiot and has put the wrong address in myself.