Strange messages from sendmail.

["Lic. Rodolfo Gonzalez Gonzalez" <rgg () SOLARIUM CS BUAP MX>]

Hello, I got this from sendmail-8.9.3-15 in a RedHat box:

Dec 25 11:00:17 mail sendmail[3873]: LAA03873: <^B^CRm\@JqqR.^^+
b^^^E2m^PH1QhO5^S9^_yt^O/]U7h~E^U]^ReKWF)I+YY^S%%9F'_^D3Vrg-^Ew^Ycc^ILmU;H7L^Y^W
c^BfK/Y;M%S\y?t:^XNw^DMvz^]^X-c6u"1^\ZKt1]AH^MFb/1e^C^B^A^yrgn^EbW^I

Dec 25 11:04:09 mail sendmail[3884]: LAA03884: <r#^PZkIY^FjuY@>... Address
contained invalid control characters
Dec 25 11:04:28 mail sendmail[3886]: LAA03886: <^G^Ck^N@4^\
^RK*^LHR$Y^H.QY`~Y^X>... Address contained invalid control characters

Dec 25 11:06:18 mail sendmail[3890]: LAA03890: <\\If^[`@++^V^H>... Address
contained invalid control characters

Dec 25 11:10:29 mail
sendmail[3899]: LAA03899: <rv{\177N|hX^D@Vc@@`^Q@VP.<a>...
Unbalanced '<'Dec 25 11:16:35 mail
sendmail[3912]: LAA03912: <^^}>... Address contained
invalid control characters



and so on. Could they be som kind of exploit or just junk sent to port
25?.

Regards,
Rodolfo.