sending email to all customers error

Hi - I tried to send an email to all of my customers yesterday and zencart reported back saying that there was an error and i should check the admin>configurations>email options

I can not see there being any issues with the settings as the settings are the same as my other sites which dont have any issues and they are hosted on the same server. I am using php

However when i sent this email even though zencart came back with a error i got a number of failed delivery attempts to my inbox - So i am suspecting that the emails did get sent out. I have over 600 customers in my store so its only fair to say i will get a number of failed delivery attempts.

Im not sure if someone could assist me on this to find out why this is happening.

I am a little concerned as i was reading through one of the failed delivery attempt emails and it mention es something about being blacklisted. Maybe someone knows a little more if this is with me or with the recipient

Connected to 194.154.164.153 but sender was rejected.
Remote host said: 550-ATLAS(2503): 69.93.139.20 is blacklisted and not
authenticated. Please
550-request delisting via the following link:
550 Listed in PSBL, see http://psbl.surriel.com/listing?ip=69.93.139.20.

Best to contact your Hoster and explain the problem to them. If they have limit as to how many eMails can be sent per hour, which is quite common and could be less than 600.

As to the IP blacklisting, who's IP is it?

Hi thanks for the reply

Yes my host has a limit of 500 emails per a hour

im not sure whos ip that is - but it was under - we tried to deliver your email to [email protected] and then the rest of the text pasted in my first post was given

so i believe its for one of the email subscribers

i have been advised to use phplist but is there any point if zencart already has a great email section?

thanks

abs