diff --git a/app/src/main/java/eu/faircode/email/MailService.java b/app/src/main/java/eu/faircode/email/MailService.java
index 06f33403c5..620c0a007b 100644
--- a/app/src/main/java/eu/faircode/email/MailService.java
+++ b/app/src/main/java/eu/faircode/email/MailService.java
@@ -124,7 +124,7 @@ public class MailService implements AutoCloseable {
             properties.put("mail.imap.starttls.required", Boolean.toString(!insecure));
 
             properties.put("mail." + protocol + ".connectionpool.debug", "true");
-            properties.put("mail." + protocol + ".connectionpoolsize", "2");
+            properties.put("mail." + protocol + ".connectionpoolsize", "1");
             properties.put("mail." + protocol + ".connectionpooltimeout", Integer.toString(POOL_TIMEOUT));
 
             properties.put("mail." + protocol + ".finalizecleanclose", "false");