What's a good [desktop based] email-blasting software?

Don't get me wrong, I don't want to send out loads of spam (although if that's what you do, more power to you). What I'm wanting to do is to send out emails to my mailing list from my desktop (windows or linux).

The reason I want to use a desktop-based client is because I have a sign-up form on my site that people input their info into, and weeks later, I send them updates. WEEKS LATER is a bit late, and many people forget that they signed up and send my emails to their spam box, resulting in MailChimp getting angry at me (it's only a .8%, but they still get angry) and locking down my account...

Is there a good software that accepts/uses custom fields (Name, Email Address, Other Stuff, Etc.) in the email message?

Also, does anyone have a good WordPress/PHP Script to capture email addresses into a CVS file?

Another benefit of a desktop-based client is that I can go to a coffee shop, write the email, blast it out, and not have to worry about my home IP getting burnt (or load up some proxies, etc.).

I think SendBlaster could help you for blasting. For capturing email addresses, use unbounce.com or OptinScript (WP plugin) + GetResponse.

Ty Cap'n. Appreciate the help

you could try Gammadyne mailer - it's fairly good and customizable

My vote goes for sendblaster, too. It's an affordable application which offers pretty good performance and lots of advantages for a desktop based emailing solution. It also accepts/ uses custom fields. I've been using it successfully for a few campaigns.

However, you need to consider signing-up for an SMTP provider and link it to sendblaster. Also you should have your own website and setup its DNS zone to work with the SMTP you have signed up for (this is only if you want your clients to see that you are sending emails from your own domain). You can find cheap SMTP's (like mailjet and a few others) which will inbox pretty good. And they are also offering guidance on how to link their solution to Sendblaster and also how to setup the DNS zone.
Using a public IP (like the one of a coffee shop) will probably deliver your messages right into your clients' spam folders.

Sendblaster is the best choice for me

I've used both Gammadyne Mailer and Sendblaster and prefer GM. It has a lot more features, and can read email addresses directly from your CSV file. Either way, like dbk03 was saying, you will have to relay through an SMTP server.

Thank you for the useful information.