diff --git a/requirements.txt b/requirements.txt
index 85338aa..7c9b022 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,12 +9,12 @@ publicsuffix2>=2.20190812
 xmltodict>=0.12.0
 geoip2>=3.0.0
 imapclient>=2.1.0
-mail-parser>=3.11.0
 dateparser>=0.7.2
 elasticsearch>=6.3.1,<7.0.0
 elasticsearch-dsl>=6.3.1,<7.0.0
 kafka-python>=1.4.4
-mailsuite>=1.5.1
+six==1.13.0
+mailsuite>=1.5.3
 nose>=1.3.7
 flake8>=3.7.8
 doc8>=0.8.0
diff --git a/setup.py b/setup.py
index 49f0216..edbb8ae 100644
--- a/setup.py
+++ b/setup.py
@@ -100,7 +100,7 @@ setup(
                       'requests>=2.22.0', 'imapclient>=2.1.0',
                       'mail-parser>=3.11.0',
                       'dateparser>=0.7.2',
-                      'mailsuite>=1.5.1',
+                      'mailsuite>=1.5.3',
                       'elasticsearch>=6.3.1,<7.0.0',
                       'elasticsearch-dsl>=6.3.1,<7.0.0',
                       'kafka-python>=1.4.4',