At the very beginning of your service you should be aware that your outbound email will be rate-limited to much lower levels than normal, specifically to the large ISPs such as Yahoo, Hotmail, AOL, etc. This is because it is the first time these ISPs are interacting with your From domain and our IP address. These throttling restrictions will begin to loosen up over the first 3 to 4 weeks as these ISPs become familiar with your outbound email activity. AOL in particular will defer your email for almost the entire first 24 hours until they begin to loosen up the restrictions and allow your messages through.
SocketLabs takes great care to monitor this warm up period and assure things go smoothly. The biggest issue during this period is typically the number of bad addresses passed to any one ISP and the number of SPAM complaints you receive about your email. Either or both of these factors will affect your delivery during this period and potentially prolong the rate-limiting you are experiencing. SocketLabs traps all bad addresses and complainer addresses in a suppression list to eliminate repeat problems.
At SocketLabs we strive to best serve our customers and understand that, for some businesses, significant delays can cause issues with your customers. You can request to have these throttling limits increased more quickly, if they are adversely affecting your business, by opening a support ticket.
We will do our best to push the throttling limits to as much as any given ISP will allow. Keep in mind that we do not control the warm-up rate or length; the ISP does this. We do our best to manage this process without adversely affecting your account.