erro ao solicitar anexo via webmail – resolvido

Olá a todos, gostaria de agradecer a todos da comunidade e pedir uma ajuda, utilizamos o envio de e-mail via webmail, mas ao criar uma nova mensagem e anexar algo o mesmo retorna o seguinte erro:

ERROR

The requested URL could not be retrieved

While trying to retrieve the URL:

The following error was encountered:

The request or reply is too large.

If you are making a POST or PUT request, then your request body

(the thing you are trying to upload) is too large. If you are

making a GET request, then the reply body (what you are trying

to download) is too large. These limits have been established

by the Internet Service Provider who operates this cache. Please

contact them directly if you feel this is an error.

não estou conseguindo compreender o motivo, alguém já teve este tipo de problema?