This kind of thing really infuriates me...

[#1]

I recently purchased a piece of software. When loaded I couldn't use it until I registered it (remember this was bought and paid for) Needing to register is not unusual, the usual method is to complete an online list, that often requires an email address. With tick boxes to NOT receive any info/sales bumff etc. That mostly don't work.
On this occasion a telephone number was supplied, answered but a more than polite agent who would give me a release code for the software that I had bought and purchased!!
"Can I have your email address please" reply "why" reply "I need it to get the release code" I rattled off some gobbledygook that sounded like an address, short pause, "we show your address as <giving my correct address> is that right" Now I was getting annoyed, "Please just give me the release code" reply "I can't do that sir unless you confirm your email address" my reply "only on the absolute premis that I am not inundated with my inbox filling with your unwanted mail" response "I can categorically confirm that you will not receive any correspondence from us or any third party if you do not wish it" I confirmed my address somewhat reluctantly and received the release code.
Within less than 24 hours I had received the first circular email from the company!!!
This is a similar situation to buying anything from a high street store such as Currys or Comet to name two, where you can't get past the till point without leaving your life history <I accept that if purchasing TV kit an address has to be taken for TV licence purposes> But, why can't you just pay your money and leave?

[#2]

A variation on this by Norton. One purchases a CD and installs the product with the activation code provided. One is then asked to provide an email address to register the product to "improve support". The product works without registration but periodically the invitation is repeated. The only way to make it go away (other than providing a disposable or perhaps fictitious email address) is to click "Remind Me Later". There is no "I do not wish to to register" option.
(I am now aware of decent free alternatives to Norton so let's not spend time discussing why I purchased the damn product in the first place!)

[#3]

I had similar years ago with a bit of software I bought. Serial number inside wasn't accepted by their own software and it took around 15 emails to and from the company before they would give me a serial for the thing I had just bought. Even then they supplied me with 3-4 that didn't work.
Sure enough I started to get the junk mail not long after so their domain got blocked 
Halfords are just as bad, one email to their customer service department and they've put me on their list too. Luckily I sent the email from a disposable email address which I've only used for them so the day I get one email from another company  they'll have some explaining to do.

[#4]

How would they respond if you said you did not have an e-mail address ?
They would know you were likely to be telling lies but are they going to tell you as a customer you are a liar. ?
Long time since I purchased any software and having moved to Linux I suspect I may never need to purchase any software again.

[#5]

I've often used me@me.co.uk but if that gets rejected I then use madeupname@madeupname.co.uk.
What I hate is when you want to make a one-off purchase to an online store and you have to register.
Normally they don't get my custom but there has been occasion where it is the only place I could find what I want and you have to give a correct email becuase you need the invoice, etc.

[#6]

Why don't you use the catchall to collect the emails and create a one of address such as thisshop@username.plus.com then if it starts getting spam black hole it

[#7]

@oldjim Was your suggestion aimed at me?
If so then I do that occasionally but my gripe was really about having to register when I know I will never use the same site again or, if I do, it would be a long time off and I'd rather not have them keeping my details for that time.
So many site do allow you to just make the purchase with having to register but offering that as a choice if you wish.

[#8]

I agree with that - it does annoy me when a store won't accept a purchase without creating an account although, having said that, Amazon do it as a method of tracking orders/questions/returns etc. so there may be a good reason for it

[#9]

Quote from: Oldjim

Why don't you use the catchall to collect the emails and create a one of address such as thisshop@username.plus.com then if it starts getting spam black hole it

Yahoo email is very good for that. You can create up to 500 disposable email addresses and delete/reinstate as needed. It's very good and I've been using it for a good couple of years now.

[#10]

Agree with Sprite, Yahoo Is what I use, Actually I recently bought a Wii game from grainger games online and was quite taken back when I could actually buy It without having to register. More companies could follow suit.
From grainger games.

Quote

Order Tracking For your convenience, it is possible to buy from Grainger Games without setting up an account. However, we recommend that you create a user account so that you can store your delivery and billing details, your payment details and be able to track your order. For our standard deliveries you will be able to see when your item was dispatched. If you choose the special delivery option (additional costs apply) you will also be given a tracking number so you can keep up to date with where your parcel is in the Royal Mail system.