Sending e-mails

[BlanchardN]

Hello! I'm a fairly new user to roundcube.  I need to send out a generic e-mail to 700 people (blind carbon-copied so that others can't see the addresses of everyone else).  Does anyone know what the maximum number of e-mail addresses is that can be placed in the BCC field at one time?  I don't mind doing several big batches, but I'm not sure I want to do 100 batches!!  Any help or guidance would be appreciated.  Thanks so much!

[SKaero]

The limit would be decided by the mail server not RoundCube, check with your hosting provider as many of them don't allow bulk mail to be sent.

[dbaral]

how to resolve this error message.

Unfortunately, messages from 202.70.94.251 weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to Troubleshooting. (in reply to MAIL FROM command))

thanks in advance.