UTM 9.6 IMAP Access to internal Exchange-Server

Hi there,

i want to access my internal Exchange Server using IMAP ( TCP 143 ) from the Internet. I´m using UTM9 ( 9.605-1 ) .

I configured the following rule ( see Attachment )

But this seems to be not 100% correct ? Because in the firewall-Log i can see the following:

2019:09:15-14:47:31 sphsutm1 ulogd[1871]: id="2001" severity="info" sys="SecureNet" sub="packetfilter" name="Packet dropped" action="drop" fwrule="60001" initf="eth0" srcmac="xx.xx.xx.xx.xx.xx" dstmac="yy:yy:yy:yy:yy:yy" srcip="93.193.11.2" dstip="192.168.2.107" proto="6" length="52" tos="0x00" prec="0x00" ttl="122" srcport="54398" dstport="143" tcpflags="SYN"


192.168.2.107 is the UTM´s external-ip 

Do you have any idea?

Thx in advance

Chakoe