On 6/20/2011 9:52 AM, Valdis.Kletnieks@vt.edu wrote:
On Mon, 20 Jun 2011 09:26:30 EDT, Steve Richardson said:
*definitely* concerns me. One thing they do say is that they need several IPs per block to assign to their MTAs to handle such a large amount of email (3 to 5 million per day). Being primarily focused on layers 1 through 4, I don't have an incredible amount of experience with high volume email server configuration, so I have no idea if they are feeding me a line of BS or not. It's BS. 5M a day is only about 60 per second, not at all a problem for a single IP address running properly configured SMTP software.
For comparison, in the mid-90s, I was moving 1M RCPT TO's a day (and probably half that number of envelopes) on a Listserv host using Sendmail on an IBM RS6000-220 - a whole whopping 66MZ Power 604E processor and something like 64M of RAM (The same basic firepower as an old Apple 6600 Mac, if you remember them...) Doing 10M messages a day on a single box is *easy* these days - the hardest part is getting a disk subsystem that survives all the fsync() beating most MTAs like to dish out....
Well... 10M messages per day on a single box today would be fine for hardware power, if most messages are accepted remotely on the first try, but not necessarily doable in the SMTP environment of today. Mail servers that send a lot of email have to hold a lot higher percentage of messages in queue for longer today due to greylisting and other deferrals - particularly from freemail sites. Your customer should only need X addresses per block for SMTP load sharing if they are going to have X number of physical servers. If they are not going to have that many physical servers, then multiple addresses in the same block per server provides no additional throughput and could only be for block avoidance. SMTP servers do most of their work managing mail queues - accepting new messages into queue, keeping track of messages in flight (those that failed and need to be retried), spoon feeding messages out to broken MTAs, etc... more IPs per box doesn't help this. Someone who expects to be "blocked occasionally" would only need two (or a few...) address blocks. Someone who expects to be "blocked all the time" would need *many* different discontiguous address blocks. Are you getting spam complaints for their current blocks at an unreasonable (to you) rate? Are they doing all the right things with SPF, DK/DKIM (not an invitation for a holy war on whether or not these are good or useful)? If I put my tin foil hat on for a moment, I might suspect that your email marketer may be feeling the pinch of the economic downturn and might be considering implementing less scrupulous practices than they have followed in the past. Even with my tin foil hat blocking out external voices... most internal voices agree that this sounds spammy. -DMM