We have a couple different speed options and you can customize as well the defaults are:
120 Emails per hour
500 Emails per hour
1500 Emails per hour
3000 emails per hour
5,000 emails per hour
10,000 emails per hour
20,000 emails per hour
40,000 emails per hour
50,000 emails per hour
Warming up IPs works if you have little to no hard bounces. Any hard bounce rate greater than 1% can still ruin your IP reputation. Below we have a warm up period for a 30 million account. Each day, there is a different amount you should sent out.

Day 1 1000
Day 2 2000
Day 3 4000
Day 4 7000
Day 5 11000
Day 6 18000
Day 7 24000
Day 8 40000
Day 9 60000
Day 10 90000
Day 11 140000
Day 12 180000
Day 13 220000
Day 14 300000
Day 15 500000
Day 16 650000
Day 17 800000
Day 18 1000000
Day 19 1200000
Day 20 1500000
Something as simple as a subject line can make all the difference. With our system, you can perform an A/B campaign to test out different subject lines. Our system will then report to you the opens for certain subject lines used.

Make sure to keep your message clean and simple. Don't use key words that will trigger spam filters. You can also check your messages for spam triggers through our system before you send your message out.
Our system accepts either .csv (comma separated values) files, .txt, .xls, zip files containing (.txt, .csv, .xls) files up to 90mb.

For format, the list needs to be one email per line. If you have multiple columns, there has to be a column called "email" in order for our system to pick it up.