Mailgun!

Scalable email delivery for transactional emailSendGrid transparently handles DKIM, SPF, ISP rate limits, content inspection, bounces, and spam reports to help users achieve higher deliverability. SendGrid integrates in minutes by just changing three SMTP settings.

SendPulse maximizes the core metric of e-mail marketing - newsletter open rate - atomatically. We collect tons of data about billions of subscribers in our system and predict the best time and channel for each subscriber when to deliver the next message to him. In a result our customers see 50% open rate increase in average.

Elastic Email offers an SMTP Relay, HTTP API, and fully featured browser based UI for managing marketing and transaction email.

Cloud Emailing by Mailjet. Create, send and track your marketing and transactional emails. Easy SMTP integration & cheap rates: boost your deliverability now!

1and1Mail gives every small and medium business the ability to easily create, schedule and send personalized mass emails, manage email contacts, and design email newsletters.

Zoho Campaigns is an email marketing automation software that helps you deliver the right message to your audience at the right time. With Zoho Campaigns, you can easily create an email campaign, send it to your recipients, share it on social media, and track the overall performance of your campaigns. The software also lets you set workflows and create a series of emails to keep your subscribers engaged.

Send emails and know when they were opened. Keep detaile email logs to who they were sent and when. A memo system to help organizations notify thier employees and keep everyone on the same page. Simple and easy to use email memo service.

Postmark removes the headaches of delivering and parsing transactional email for webapps with minimal setup time and zero maintenance. Send API and SMTP interface.

Smart SMTP server for email marketing. Personal server distribution, automatically results in 5 minutes, their ' senders, automatic replies, the statistics in real-time and friendly support for each

turboSMTP is a world-leading SMTP provider.Our outgoing mail server guarantees secure SMTP relays and it's ideal to send transactional emails. It also provides an amazing SMTP API for developers of cloud applications and a free SMTP server service.

SMTP2GO is an email service provider, performing the task of reliably delivering transactional and marketing emails, and providing reporting tools to track and visualize what is happening with outgoing emails.

AltosMail is a mail marketing software.