Sendy - This software has pretty much made all other mailing list servers and application obsolete. I've been using it as a replacement for my mail server and it works brilliantly. Of course you do need an Amazon SES account, and you do have to pay to send through Amazon, but it's very cheap (.10 per thousand).  *After using Sendy for almost one year now, there are some limitations, that can be addressed. 1.) It's impossible to search all of your lists to find an email address to delete, instead you have to manually go into each list, one by one to do it. This is not fixed yet, hopefully soon. 2.) There are no html templates, or any way to save them.  This is a glaring problem, however, there are fixes posted in the Sendy Forum at this post, which let you install either TinyMCE, or CKEditor (also see this modification to let you upload/use images with CKEditor, it's already included in the TinyMCE version) and use that to create html templates in the Campaign window of Sendy.  You can also use the free Template builder over at Campaign Monitor to build up html templates for use in Sendy.

G-Lock EasyMail 7 - Finally this solution for the desktop looks promising and able to handle large list sending. You can even integrate this directly with your already hosted MySQL email databases that are online - this allows an incredible flexibility of trying it out using your current database. See more about it at this link. It also works with Amazon SES - so you could move mailing to Amazon at another time, if you want to.  This is the best system for moving from an online mail  server to desktop. Highly Recommended. (Order online at this link & use coupon: 4F07E3BD27 for a 20% discount).  They also make G-Lock Email Processor (order Email Processor) and G-Lock Advanced Email Verifier (order Advanced Email Verifier) as well as GLock Analytics, and HotEmailTemplates.

G-Lock Advanced Email Verifier - Verify the email addresses on your list, remove duplicates, and check that the addresses are good. The best software available for handling address verification on your own desktop.  (Order online at this link & use the coupon: 4F07E3BD27 for 20% discount).

Google's FAQ on Spam suspicious emails - Learn why Google may be banning your emails, or moving them to the Junk Mail folder, or Promotion Tab.

EmailAnswers.com - High end email list verifier that goes way beyond normal verification services.

Dispostable - The absolute best spot to get a free disposable (throw-away) email address, which is good for only a few days, and will let you test your autoresponder.

HTML Email Inline Styler - Use this free online app to turn your CSS code into inline styles that you can embed in your email messages. 

Spam Blocking - Need to block SPAM, there are only a few alternatives: 1.) forward (or have Google retrieve by POP3, see this Google FAQ) email sent to your spammy account, or 2.) implement all of these features in this Forum Post to try to get spam blocked and removed. Also see this SpamAssassin Trainer script.

MadMimi - An excellent and inexpensive autoresponder that will allow you to import unlimited contacts into your lists without having to require opt-in confirmations. There is nothing else like it at the moment. For the features it offers, this is the best price you will find on an autoresponder. No longer recommended, staff does not pay bills, and therefore cannot rely on their services. Excellent articles on their blog such as this one: 4 Tips To Increase Your Email  Marketing CTR.

Gmail Promotion Tabs - How they affect your inbox open and click through rates, find out in this excellent article.

MyMail - The first scalable WordPress mail plugin, supports Mandrill, Amazon SES, and other email providers. Ties in beautifully with your blog, sold through CodeCanyon.  Large list sending will be tested soon, and reported here.  Also see IMSC Rapid Mailer (below).

IMSC Rapid Mailer - A new WordPress enabled mailer that also features paid list signups.  I will be doing a full review of this mailer soon. It does work, but only for smaller lists, and is not recommended for large-scale emailing. Also see MyMail (above).

Fulcrum Technology - The leaders in Email ROI studies. Check out their 10 point checklist, and learn all you can about increasing email ROI through this website.  Their Email Marketing Blog is well worth the read, excellent. The website also features great articles such as: Email Deliverability, Avoiding the GMail Spam Filter and more.

Compare Bulk Email Service Providers - The master list, compare pricing and details on all major email providers. A great resource.  Also see: Email Marketing Software Comparison

allcontact - An interesting approach to autoresponder/contact management. Allows you to contact by phone, email, CD/DVD, or standard mail.

campaigner - Finally a company offering decent prices for larger lists. Worth a look and worth trying.

Campaign Monitor Free Template Builder - An excellent online email template builder.

SendGrid - An excellent tool for sending large volume email. Use the SendGrid servers to send all of your email. They also have an excellent blog at: http://blog.sendgrid.com

How To Warm Up A IP Address for email sending - Great blog post from SendGrid about how to warm up an IP address so that you can send large volume email.

Aweber - If you want the very best, including detailed stats, analytics and autoresponder statistics you should consider Aweber.

GetResponse - Another great choice for an autoresponder (with video/audio hosting included). Great deliverability and flexibility too, similar to Aweber, but not as widely supported.

Comm100- A completely free email service, and a live chat system along with email ticketing help desk. This open source alternative may be just what you are looking for.

Crafty Syntax - An excellent LiveHelp operator software that is inexpensive and offers many options such as multiple operators, history reporting, and more.

XSitePro Email / Mailing List Server Scripts Links

Sendy - This software has pretty much made all other mailing list servers and application obsolete. I've been using it as a replacement for my mail server and it works brilliantly. Of course you do need an Amazon SES account, and you do have to pay to send through Amazon, but it's very cheap (.10 per thousand).

MyMail - The absolute gold standard for sending emails/newsletters/autoresponders directly out of WordPress for a reasonable price ($39.00).  Various delivery methods available including (Mandrill, SMTP, Amazon SES, SendGrid), and full suites of email templates.

MailPoet (formerly WYISJA) - a great WordPress based mailer that can handle larger volumes. Most powerful for newsletter sends, as it can bundle up all posts within a category and send them on a regular basis as a newsletter (all automated).  They also maintain a blog over at: MailPoet Blog  with great articles like: Case Study: Baking Success With BuddyPress and Newsletters, and this link of 40 Hosting Companies Email Limits.

ListMailPro - I use this mailer and autoresponder softwar to manage my own lists, on my own mail server. If you require a mail server this is your best option. It is fast and very efficient and can easily handle very large lists. I've had over 200,000 email addresses in one installation. I currently run around 50,000 active signups on my ListMailPro VPS server.

Oempro - Octeth continues to innovate with their Oempro software. A dedicated mailer, Oempro features excellent API Integration as well as Plugin support for just about any situation. There is an excellent, and active support forum where you can learn everything you need to about sending rates, deliverability, and technical email server setup. For more details also see the company blog. Excellent articles on deliverability and other Email issues can be found on the SendLoop blog such as this: Recipient Engagement, the only way to ensure better GMail delivery, or The 5 Essentials of a Well Designed Email.

Active Campaign - A server based mail list solution. Includes full email reader previews (for major services HotMail, Yahoo, GMail), and social bookmarking links included in your emails, trending stats and too many features to describe here. For more information see their blog (especially this valuable post about the 128 ways to optimize your Email Marketing Campaign ). You can also see how they like to listen to their users: which new features they should add first. Their Knowledge base gives details of the entire Active Campaign software package and it's capabilities.

phplist - A useful free and open source alternative. I have previously tested and even used this software once before. It is freqently updated and has RSS feed links, scheduling alternatives, detailed list segmentation, click tracking and many other features. Worth looking at, especially if you want to integrate with Amazon SES (simple email system).

OmnistarMailer - A server based mailer script with a track record that includes features such as built in triggers and even automated split testing. Previously (about 5 years ago) it was a bit slower on it's mailing rate. The OmnistarMailer blog is a great place to read about it. They also include email templates.

Arial Software - A windows based application that can handle very large volume sending.  Their Daily Blog has some great informative articles such as this one: How Email Flows Through The Internet.

NowSMS - This provider fully supports CMS, SMS, WAP push and is a less costly alternative.

GoGVO - From the previous company Kiosk, they have put together an excellent recorded audio/video conference center for online marketing. Competitive and lower priced than the bigger names (such as Goto Meeting).

It's getting more and more important to have a good responsive graphic oriented Email template to use when sending to your customers. It should match the brand you portray on your website and be clean and simple easy to read.  Sites below help with that.

Zurb Library (Playground) Responsive Email templates- Get geared up for a nice responsive design with these free Zurb templates, highly recommended. Pull them into XSitePro for design work, then view a preview of the page and save the html. More can be found at the Zurb Blog, including details on making them work for Outlook 2007.

MailChimp Inline Styling Tool- A great way to setup inline CSS styling as GMail will strip out any that is not inline. Here's another Inline styling tool.

Use these sites as references to new ways to market using autoresponders.

EmailTracking.net - home of interesting articles and videos such as: Email Basics & Best Practices - a great video on basic Email practices.

Why Email Marketing is NOT Dead - Great article from Sean Donahoe about the power of email marketing.

ARM 2.0 - Autoresponder Madness 2.0-Andre Chaperon has a unique way of including stories in your emails, and how to build in mini product launches in 3 sequence emails which can be evergreen. One of the best resources when it comes to writing powerful marketing messages in your email autoresponder series. For a nutshell diagram: see this document. To signup for his free course (*highly recommended), check out his: Lucrative List Building Bootcamp.  Also see this excellent recorded interview with Andre on ClickBank Insider Radio: Episode 8, Email Marketing with Andre Chaperon in this interview he discusses the basics of ARM, and how he based it on Jay Abraham's: Strategy of Pre-eminence, also see this link on how to create an abundance mindset which will help you as give away more content for free: How To Create The Abundance Mindset.

Affiliate Bully-More details from Andre Chaperon on how to market responsibly with email, great material.

Tiny Little Businesses-Another course from Andre Chaperon, currently closed, but worth it just to read the comments, you will pick up some great tips.