When you put down a "contact us" page do you have just an e-mail link or a form that automatically submits to e-mail? If you have an e-mail is it contact@zxy.com or admin@xzy.com?

I have a form. The form fields prompt people to include all the information I'll need to respond thoroughly to their question. I'm also able to add a note to clients asking them to file a support ticket rather than use the contact form.

I regularly change the email attached to my contact form (once every few years) because after a few years, spam starts coming to that address. It's an email address that isn't used for anything but that contact form; but spammers still get ahold of the email address and add it to their lists.

I would recommend against using something common like "sales", "presales", "contact", support", or "admin". Those "default" email addresses get added to spammers' lists largely because they know that many site owners will use them, and so they can have a better chance of sending spam off to someone who will potentially click the link (they hope). If you use a particular phrase and then append some numbers to the end of it (one or two, not five or seven), you can rotate that email address at need but still keep most of it the same. This won't help someone who submitted a question two years ago and now tries sending an email to that address; but it will save you the time thinking up new, sufficiently abstract email addresses each time you've got to rotate one out.

My vote goes on the form option. Although i don't have a hosting site, which requires feedback, i would go with the form option because:

Lot of people don't have any email client set up, and therefore must first login to their email accounts, paste the email and then write you the note...
Second, many of them can't really make a difference of what is relevant to write and mention and what isn't... Someone can email you saying that his site was down for few hours, and providing you with bunch of facts that you really don't need to solve their problem... E-mail form offers you much more - you can obbligate someone to point out why he/she is writing to you, you can put questions on which you require the answer, etc, etc... Way better!

For Sales
Its email address, which sends a email to the billing team,

For Support.
We created a custom ticket system which will then send a email by email, and sends a txt message to the support teams on Call mobile,
giving the 24/7 support our customers expect.

all emails that sent goes to a mobile phone outside normal support hours, so for sales and everything we supply a true 24/7 support.

but there is one down side in this, the on call mobile that has all these email and ticket notifcation is to my mobile so most nights I get sleepless.

I dislike the idea of offering as the first point of contact, the email address. I don't really know why this idea puts me off-just like a phone number, being too personal for the first access for a potentially angry client. I personally would be less likely to fire off multiple forms, instead getting it right the first time with the form rather than an email.

And as Lesli said, you can hand hold, you can prompt at every step of the way to get the information that you need.

Guess I'm going to have to brush up on my form HTML. I've often wondered how many contacts with e-mails get mined for spam compared to actual business e-mails.

Lesli if you don't mind me asking: do you also offer contact through an online chat program or instant messenger or just e-mail and form submission?

I see more and more chat clients and instant messenger contacts being offered on sites but can't help but think it must be frustrating to the client and a hassle for the host.

I don't have outward-facing online chat - I don't have the personnel to staff it for clients and potential clients, and don't want to have a third-party group sending canned answers. A few of us take turns "staffing" the client-only chat during set hours; but there aren't too many pings through that.

If you're concerned about business emails getting halted by spam filters, set your form up to cc: the emails to a few different addresses on different servers (your own, gmail, some other free provider of your choosing.) With three servers "watching", chances are any business email will get through at least one of those locations - and then you can whitelist that IP if necessary.

I'll go for FORM and if possible with CAPTCHA verification.

That depends on the type and purpose of your website. Some webmasters are just displaying email address as an image. That might be helping them to get only serious inquiries.

We use email as well as ticketing system.
Forms is a no-no for us as we will get large chunk of spam (worse than emails) even though it is equipped with the latest captcha system.

I go for the form just because you will come across a few people who do not have a defaulted email system set up and if you have it go to an address, they will not send you their info.