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smtp outgoing mail being blocked by firewall

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  • Last reply by Matt

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Hi, Thunderbird is being used to replace Outlook Express on laptops on board vessels that use a satellite based transmission system on which a firewall is in place. The incoming Server is set up and working , getting mail, however the SMPT server is being blocked by the firewall. This has been proved by taking a laptop to a location where normal broadband is available. Mail can be sent and received by Thunderbird.

We have tried many of the sugested settings as found in your help pages.

The following is some information I have received today to help fix the problem.


Those are the ports. Also it would be great to know the email domain ( ...@domain.com)

Outgoing (SMTP): Secure SMTP (SSMTP) - port 465

Incoming (IMAP): Secure IMAP (IMAP4-SSL) - port 585 IMAP4 over SSL (IMAPS) - port 993

Incoming (POP): Secure POP3 (SSL-POP) - port 995


This is information I have been asked to use. One question is the Domain name?? The email address are as follows DA41@IRLERS.ie Is the Domain name IRLERS.IE

Thanks for any help you can give me, Regards John O'Mahony Thundebird user.

Hi, Thunderbird is being used to replace Outlook Express on laptops on board vessels that use a satellite based transmission system on which a firewall is in place. The incoming Server is set up and working , getting mail, however the SMPT server is being blocked by the firewall. This has been proved by taking a laptop to a location where normal broadband is available. Mail can be sent and received by Thunderbird. We have tried many of the sugested settings as found in your help pages. The following is some information I have received today to help fix the problem. ------------------------------------------------------------------------------------------------------------------------------------- Those are the ports. Also it would be great to know the email domain ( ...@domain.com) Outgoing (SMTP): Secure SMTP (SSMTP) - port 465 Incoming (IMAP): Secure IMAP (IMAP4-SSL) - port 585 IMAP4 over SSL (IMAPS) - port 993 Incoming (POP): Secure POP3 (SSL-POP) - port 995 ------------------------------------------------------------------------------------------------------------------ This is information I have been asked to use. One question is the Domain name?? The email address are as follows DA41@IRLERS.ie Is the Domain name IRLERS.IE Thanks for any help you can give me, Regards John O'Mahony Thundebird user.

All Replies (1)

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What firewall is the rel question. Depending on the type, you may need to allow Thunderbird as a mail sending application, or simply allow it access to the internet in the firewall application.

If it it a more traditional firewall, enabling outgoing connection and the protocol SMTP on port 465 may be the thing. Basically you need to configure the firewall and asking experts in that type of firewall will return the best results.

My guess is it is probably either a port issue (outlook express is old, so the ports may well have been 25 for sending a decade ago. Not the current 465). Or an application firewall that needs to be told Thunderbird exists. But I am guessing.