Set message_linelength_limit = 204800
#MAILCHANNELS_TRANSPORTSTART
mailchannels_smtp:
driver = smtp
hosts_require_auth = *
hosts_require_tls = *
message_linelength_limit = 204800
tls_tempfail_tryclear = true
#MESSAGE_LINELENGTH_LIMIT_UNSET
headers_add = X-AuthUser: ${if match {$authenticated_id}{.*@.*}\
{$authenticated_id} {${if match {$authenticated_id}{.+}\
{$authenticated_id@$primary_hostname}{$authenticated_id}}}}
dkim_domain = ${perl{get_dkim_domain}}
dkim_selector = default
dkim_canon = relaxed
dkim_private_key = "/var/cpanel/domain_keys/private/${dkim_domain}"
.ifdef SRSENABLED
mailchannels_forwarded_smtp:
driver = smtp
hosts_require_auth = *
hosts_require_tls = *
message_linelength_limit = 204800
max_rcpt = 1
return_path = ${srs_encode {SRS_SECRET} {$return_path} {$original_domain}}
tls_tempfail_tryclear = true
headers_add = X-AuthUser: ${if match {$authenticated_id}{.*@.*}\
{$authenticated_id} {${if match {$authenticated_id}{.+}\
{$authenticated_id@$primary_hostname}{$authenticated_id}}}}
dkim_domain = $sender_address_domain
dkim_selector = default
dkim_canon = relaxed
dkim_private_key = "/var/cpanel/domain_keys/private/${dkim_domain}"
.endif
#MAILCHANNELS_TRANSPORTSTOP